This file contains any messages produced by compilers while
running configure, to aid debugging if configure makes a mistake.

It was created by iperf configure 3.10, which was
generated by GNU Autoconf 2.71.  Invocation command line was

  $ ./configure --prefix=/usr --build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu --mandir=/usr/share/man --infodir=/usr/share/info --datadir=/usr/share --sysconfdir=/etc --localstatedir=/var/lib --disable-dependency-tracking --disable-silent-rules --docdir=/usr/share/doc/iperf-3.10 --htmldir=/usr/share/doc/iperf-3.10/html --with-sysroot=/ --libdir=/usr/lib64 --disable-static

## --------- ##
## Platform. ##
## --------- ##

hostname = localhost
uname -m = x86_64
uname -r = 5.4.0-1048-aws
uname -s = Linux
uname -v = #50-Ubuntu SMP Mon May 3 21:44:17 UTC 2021

/usr/bin/uname -p = Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz
/bin/uname -X     = unknown

/bin/arch              = unknown
/usr/bin/arch -k       = unknown
/usr/convex/getsysinfo = unknown
/usr/bin/hostinfo      = unknown
/bin/machine           = unknown
/usr/bin/oslevel       = unknown
/bin/universe          = unknown

PATH: /usr/lib/portage/python3.9/ebuild-helpers/xattr/
PATH: /usr/lib/portage/python3.9/ebuild-helpers/
PATH: /usr/local/sbin/
PATH: /usr/local/bin/
PATH: /usr/sbin/
PATH: /usr/bin/
PATH: /sbin/
PATH: /bin/
PATH: /opt/bin/
PATH: /usr/lib/llvm/12/bin/


## ----------- ##
## Core tests. ##
## ----------- ##

configure:2436: looking for aux files: compile config.guess config.sub ltmain.sh missing install-sh
configure:2449:  trying ./config/
configure:2478:   ./config/compile found
configure:2478:   ./config/config.guess found
configure:2478:   ./config/config.sub found
configure:2478:   ./config/ltmain.sh found
configure:2478:   ./config/missing found
configure:2460:   ./config/install-sh found
configure:2705: checking for a BSD-compatible install
configure:2778: result: /usr/lib/portage/python3.9/ebuild-helpers/xattr/install -c
configure:2789: checking whether build environment is sane
configure:2844: result: yes
configure:3003: checking for a race-free mkdir -p
configure:3047: result: /bin/mkdir -p
configure:3054: checking for gawk
configure:3075: found /usr/bin/gawk
configure:3086: result: gawk
configure:3097: checking whether make sets $(MAKE)
configure:3120: result: yes
configure:3150: checking whether make supports nested variables
configure:3168: result: yes
configure:3302: checking whether make supports nested variables
configure:3320: result: yes
configure:3363: checking build system type
configure:3378: result: x86_64-pc-linux-gnu
configure:3398: checking host system type
configure:3412: result: x86_64-pc-linux-gnu
configure:3453: checking how to print strings
configure:3480: result: printf
configure:3514: checking whether make supports the include directive
configure:3529: make -f confmf.GNU && cat confinc.out
this is the am__doit target
configure:3532: $? = 0
configure:3551: result: yes (GNU style)
configure:3582: checking for x86_64-pc-linux-gnu-gcc
configure:3614: result: x86_64-pc-linux-gnu-gcc
configure:4012: checking for C compiler version
configure:4021: x86_64-pc-linux-gnu-gcc --version >&5
x86_64-pc-linux-gnu-gcc (Gentoo 11.1.0 p1) 11.1.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

configure:4032: $? = 0
configure:4021: x86_64-pc-linux-gnu-gcc -v >&5
Using built-in specs.
COLLECT_GCC=x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/11.1.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /var/tmp/portage/sys-devel/gcc-11.1.0/work/gcc-11.1.0/configure --host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --prefix=/usr --bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/11.1.0 --includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/11.1.0/include --datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/11.1.0 --mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/11.1.0/man --infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/11.1.0/info --with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/11.1.0/include/g++-v11 --with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/11.1.0/python --enable-languages=c,c++,fortran --enable-obsolete --enable-secureplt --disable-werror --with-system-zlib --enable-nls --without-included-gettext --enable-checking=release --with-bugurl=https://bugs.gentoo.org/ --with-pkgversion='Gentoo 11.1.0 p1' --disable-esp --enable-libstdcxx-time --with-build-config=bootstrap-lto --enable-shared --enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu --enable-multilib --with-multilib-list=m32,m64 --disable-fixed-point --enable-targets=all --enable-libgomp --disable-libssp --disable-libada --disable-systemtap --disable-valgrind-annotations --disable-vtable-verify --disable-libvtv --without-zstd --enable-lto --with-isl --disable-isl-version-check --enable-default-pie --enable-default-ssp
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 11.1.0 (Gentoo 11.1.0 p1) 
configure:4032: $? = 0
configure:4021: x86_64-pc-linux-gnu-gcc -V >&5
x86_64-pc-linux-gnu-gcc: error: unrecognized command-line option '-V'
x86_64-pc-linux-gnu-gcc: fatal error: no input files
compilation terminated.
configure:4032: $? = 1
configure:4021: x86_64-pc-linux-gnu-gcc -qversion >&5
x86_64-pc-linux-gnu-gcc: error: unrecognized command-line option '-qversion'; did you mean '--version'?
x86_64-pc-linux-gnu-gcc: fatal error: no input files
compilation terminated.
configure:4032: $? = 1
configure:4021: x86_64-pc-linux-gnu-gcc -version >&5
x86_64-pc-linux-gnu-gcc: error: unrecognized command-line option '-version'
x86_64-pc-linux-gnu-gcc: fatal error: no input files
compilation terminated.
configure:4032: $? = 1
configure:4052: checking whether the C compiler works
configure:4074: x86_64-pc-linux-gnu-gcc -O2 -pipe -march=x86-64 -frecord-gcc-switches  -Wl,-O1 -Wl,--as-needed -Wl,--defsym=__gentoo_check_ldflags__=0 conftest.c  >&5
configure:4078: $? = 0
configure:4128: result: yes
configure:4131: checking for C compiler default output file name
configure:4133: result: a.out
configure:4139: checking for suffix of executables
configure:4146: x86_64-pc-linux-gnu-gcc -o conftest -O2 -pipe -march=x86-64 -frecord-gcc-switches  -Wl,-O1 -Wl,--as-needed -Wl,--defsym=__gentoo_check_ldflags__=0 conftest.c  >&5
configure:4150: $? = 0
configure:4173: result: 
configure:4195: checking whether we are cross compiling
configure:4203: x86_64-pc-linux-gnu-gcc -o conftest -O2 -pipe -march=x86-64 -frecord-gcc-switches  -Wl,-O1 -Wl,--as-needed -Wl,--defsym=__gentoo_check_ldflags__=0 conftest.c  >&5
configure:4207: $? = 0
configure:4214: ./conftest
configure:4218: $? = 0
configure:4233: result: no
configure:4238: checking for suffix of object files
configure:4261: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  conftest.c >&5
configure:4265: $? = 0
configure:4287: result: o
configure:4291: checking whether the compiler supports GNU C
configure:4311: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  conftest.c >&5
configure:4311: $? = 0
configure:4321: result: yes
configure:4332: checking whether x86_64-pc-linux-gnu-gcc accepts -g
configure:4353: x86_64-pc-linux-gnu-gcc -c -g  conftest.c >&5
configure:4353: $? = 0
configure:4397: result: yes
configure:4417: checking for x86_64-pc-linux-gnu-gcc option to enable C11 features
configure:4432: x86_64-pc-linux-gnu-gcc  -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  conftest.c >&5
configure:4432: $? = 0
configure:4450: result: none needed
configure:4566: checking whether x86_64-pc-linux-gnu-gcc understands -c and -o together
configure:4589: x86_64-pc-linux-gnu-gcc -c conftest.c -o conftest2.o
configure:4592: $? = 0
configure:4589: x86_64-pc-linux-gnu-gcc -c conftest.c -o conftest2.o
configure:4592: $? = 0
configure:4604: result: yes
configure:4623: checking dependency style of x86_64-pc-linux-gnu-gcc
configure:4735: result: none
configure:4750: checking for a sed that does not truncate output
configure:4820: result: /bin/sed
configure:4838: checking for grep that handles long lines and -e
configure:4902: result: /bin/grep
configure:4907: checking for egrep
configure:4975: result: /bin/grep -E
configure:4980: checking for fgrep
configure:5048: result: /bin/grep -F
configure:5084: checking for ld used by x86_64-pc-linux-gnu-gcc
configure:5152: result: x86_64-pc-linux-gnu-ld
configure:5159: checking if the linker (x86_64-pc-linux-gnu-ld) is GNU ld
configure:5175: result: yes
configure:5187: checking for BSD- or MS-compatible name lister (nm)
configure:5242: result: x86_64-pc-linux-gnu-nm
configure:5382: checking the name lister (x86_64-pc-linux-gnu-nm) interface
configure:5390: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  conftest.c >&5
configure:5393: x86_64-pc-linux-gnu-nm "conftest.o"
configure:5396: output
0000000000000000 B some_variable
configure:5403: result: BSD nm
configure:5406: checking whether ln -s works
configure:5410: result: yes
configure:5418: checking the maximum length of command line arguments
configure:5550: result: 1572864
configure:5598: checking how to convert x86_64-pc-linux-gnu file names to x86_64-pc-linux-gnu format
configure:5639: result: func_convert_file_noop
configure:5646: checking how to convert x86_64-pc-linux-gnu file names to toolchain format
configure:5667: result: func_convert_file_noop
configure:5674: checking for x86_64-pc-linux-gnu-ld option to reload object files
configure:5682: result: -r
configure:5716: checking for x86_64-pc-linux-gnu-objdump
configure:5748: result: x86_64-pc-linux-gnu-objdump
configure:5825: checking how to recognize dependent libraries
configure:6026: result: pass_all
configure:6071: checking for x86_64-pc-linux-gnu-dlltool
configure:6106: result: no
configure:6116: checking for dlltool
configure:6151: result: no
configure:6181: checking how to associate runtime and link libraries
configure:6209: result: printf %s\n
configure:6226: checking for x86_64-pc-linux-gnu-ar
configure:6258: result: x86_64-pc-linux-gnu-ar
configure:6344: checking for archiver @FILE support
configure:6362: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  conftest.c >&5
configure:6362: $? = 0
configure:6366: x86_64-pc-linux-gnu-ar cru libconftest.a @conftest.lst >&5
configure:6369: $? = 0
configure:6374: x86_64-pc-linux-gnu-ar cru libconftest.a @conftest.lst >&5
x86_64-pc-linux-gnu-ar: conftest.o: No such file or directory
configure:6377: $? = 1
configure:6389: result: @
configure:6407: checking for x86_64-pc-linux-gnu-strip
configure:6439: result: x86_64-pc-linux-gnu-strip
configure:6516: checking for x86_64-pc-linux-gnu-ranlib
configure:6548: result: x86_64-pc-linux-gnu-ranlib
configure:6695: checking command to parse x86_64-pc-linux-gnu-nm output from x86_64-pc-linux-gnu-gcc object
configure:6849: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  conftest.c >&5
configure:6852: $? = 0
configure:6856: x86_64-pc-linux-gnu-nm conftest.o \| sed -n -e 's/^.*[ ]\([ABCDGIRSTW][ABCDGIRSTW]*\)[ ][ ]*\([_A-Za-z][_A-Za-z0-9]*\)$/\1 \2 \2/p' | sed '/ __gnu_lto/d' \> conftest.nm
configure:6859: $? = 0
configure:6925: x86_64-pc-linux-gnu-gcc -o conftest -O2 -pipe -march=x86-64 -frecord-gcc-switches  -Wl,-O1 -Wl,--as-needed -Wl,--defsym=__gentoo_check_ldflags__=0 conftest.c conftstm.o >&5
configure:6928: $? = 0
configure:6966: result: ok
configure:7013: checking for sysroot
configure:7044: result: /
configure:7051: checking for a working dd
configure:7095: result: /bin/dd
configure:7099: checking how to truncate binary pipes
configure:7115: result: /bin/dd bs=4096 count=1
configure:7252: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  conftest.c >&5
configure:7255: $? = 0
configure:7407: checking for x86_64-pc-linux-gnu-mt
configure:7442: result: no
configure:7452: checking for mt
configure:7487: result: no
configure:7507: checking if : is a manifest tool
configure:7514: : '-?'
configure:7522: result: no
configure:8247: checking for stdio.h
configure:8247: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  conftest.c >&5
configure:8247: $? = 0
configure:8247: result: yes
configure:8247: checking for stdlib.h
configure:8247: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  conftest.c >&5
configure:8247: $? = 0
configure:8247: result: yes
configure:8247: checking for string.h
configure:8247: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  conftest.c >&5
configure:8247: $? = 0
configure:8247: result: yes
configure:8247: checking for inttypes.h
configure:8247: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  conftest.c >&5
configure:8247: $? = 0
configure:8247: result: yes
configure:8247: checking for stdint.h
configure:8247: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  conftest.c >&5
configure:8247: $? = 0
configure:8247: result: yes
configure:8247: checking for strings.h
configure:8247: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  conftest.c >&5
configure:8247: $? = 0
configure:8247: result: yes
configure:8247: checking for sys/stat.h
configure:8247: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  conftest.c >&5
configure:8247: $? = 0
configure:8247: result: yes
configure:8247: checking for sys/types.h
configure:8247: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  conftest.c >&5
configure:8247: $? = 0
configure:8247: result: yes
configure:8247: checking for unistd.h
configure:8247: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  conftest.c >&5
configure:8247: $? = 0
configure:8247: result: yes
configure:8272: checking for dlfcn.h
configure:8272: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  conftest.c >&5
configure:8272: $? = 0
configure:8272: result: yes
configure:8531: checking for objdir
configure:8547: result: .libs
configure:8807: checking if x86_64-pc-linux-gnu-gcc supports -fno-rtti -fno-exceptions
configure:8826: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  -fno-rtti -fno-exceptions conftest.c >&5
cc1: warning: command-line option '-fno-rtti' is valid for C++/D/ObjC++ but not for C
configure:8830: $? = 0
configure:8843: result: no
configure:9201: checking for x86_64-pc-linux-gnu-gcc option to produce PIC
configure:9209: result: -fPIC -DPIC
configure:9217: checking if x86_64-pc-linux-gnu-gcc PIC flag -fPIC -DPIC works
configure:9236: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  -fPIC -DPIC -DPIC conftest.c >&5
configure:9240: $? = 0
configure:9253: result: yes
configure:9282: checking if x86_64-pc-linux-gnu-gcc static flag -static works
configure:9311: result: yes
configure:9326: checking if x86_64-pc-linux-gnu-gcc supports -c -o file.o
configure:9348: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  -o out/conftest2.o conftest.c >&5
configure:9352: $? = 0
configure:9374: result: yes
configure:9382: checking if x86_64-pc-linux-gnu-gcc supports -c -o file.o
configure:9430: result: yes
configure:9463: checking whether the x86_64-pc-linux-gnu-gcc linker (x86_64-pc-linux-gnu-ld -m elf_x86_64) supports shared libraries
configure:10729: result: yes
configure:10766: checking whether -lc should be explicitly linked in
configure:10775: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches  conftest.c >&5
configure:10778: $? = 0
configure:10793: x86_64-pc-linux-gnu-gcc -shared  -fPIC -DPIC conftest.o  -v -Wl,-soname -Wl,conftest -o conftest 2\>\&1 \| /bin/grep  -lc  \>/dev/null 2\>\&1
configure:10796: $? = 0
configure:10810: result: no
configure:10970: checking dynamic linker characteristics
configure:11552: x86_64-pc-linux-gnu-gcc -o conftest -O2 -pipe -march=x86-64 -frecord-gcc-switches  -Wl,-O1 -Wl,--as-needed -Wl,--defsym=__gentoo_check_ldflags__=0 -Wl,-rpath -Wl,/foo conftest.c  >&5
configure:11552: $? = 0
configure:11791: result: GNU/Linux ld.so
configure:11913: checking how to hardcode library paths into programs
configure:11938: result: immediate
configure:12490: checking whether stripping libraries is possible
configure:12495: result: yes
configure:12530: checking if libtool supports shared libraries
configure:12532: result: yes
configure:12535: checking whether to build shared libraries
configure:12560: result: yes
configure:12563: checking whether to build static libraries
configure:12567: result: no
configure:12606: checking whether to enable maintainer-specific portions of Makefiles
configure:12616: result: no
configure:12644: checking for x86_64-pc-linux-gnu-gcc
configure:12676: result: x86_64-pc-linux-gnu-gcc
configure:13074: checking for C compiler version
configure:13083: x86_64-pc-linux-gnu-gcc --version >&5
x86_64-pc-linux-gnu-gcc (Gentoo 11.1.0 p1) 11.1.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

configure:13094: $? = 0
configure:13083: x86_64-pc-linux-gnu-gcc -v >&5
Using built-in specs.
COLLECT_GCC=x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/11.1.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /var/tmp/portage/sys-devel/gcc-11.1.0/work/gcc-11.1.0/configure --host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --prefix=/usr --bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/11.1.0 --includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/11.1.0/include --datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/11.1.0 --mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/11.1.0/man --infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/11.1.0/info --with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/11.1.0/include/g++-v11 --with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/11.1.0/python --enable-languages=c,c++,fortran --enable-obsolete --enable-secureplt --disable-werror --with-system-zlib --enable-nls --without-included-gettext --enable-checking=release --with-bugurl=https://bugs.gentoo.org/ --with-pkgversion='Gentoo 11.1.0 p1' --disable-esp --enable-libstdcxx-time --with-build-config=bootstrap-lto --enable-shared --enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu --enable-multilib --with-multilib-list=m32,m64 --disable-fixed-point --enable-targets=all --enable-libgomp --disable-libssp --disable-libada --disable-systemtap --disable-valgrind-annotations --disable-vtable-verify --disable-libvtv --without-zstd --enable-lto --with-isl --disable-isl-version-check --enable-default-pie --enable-default-ssp
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 11.1.0 (Gentoo 11.1.0 p1) 
configure:13094: $? = 0
configure:13083: x86_64-pc-linux-gnu-gcc -V >&5
x86_64-pc-linux-gnu-gcc: error: unrecognized command-line option '-V'
x86_64-pc-linux-gnu-gcc: fatal error: no input files
compilation terminated.
configure:13094: $? = 1
configure:13083: x86_64-pc-linux-gnu-gcc -qversion >&5
x86_64-pc-linux-gnu-gcc: error: unrecognized command-line option '-qversion'; did you mean '--version'?
x86_64-pc-linux-gnu-gcc: fatal error: no input files
compilation terminated.
configure:13094: $? = 1
configure:13083: x86_64-pc-linux-gnu-gcc -version >&5
x86_64-pc-linux-gnu-gcc: error: unrecognized command-line option '-version'
x86_64-pc-linux-gnu-gcc: fatal error: no input files
compilation terminated.
configure:13094: $? = 1
configure:13098: checking whether the compiler supports GNU C
configure:13128: result: yes
configure:13139: checking whether x86_64-pc-linux-gnu-gcc accepts -g
configure:13204: result: yes
configure:13224: checking for x86_64-pc-linux-gnu-gcc option to enable C11 features
configure:13257: result: none needed
configure:13373: checking whether x86_64-pc-linux-gnu-gcc understands -c and -o together
configure:13411: result: yes
configure:13430: checking dependency style of x86_64-pc-linux-gnu-gcc
configure:13542: result: none
configure:13560: checking for x86_64-pc-linux-gnu-ranlib
configure:13592: result: x86_64-pc-linux-gnu-ranlib
configure:13659: checking whether ln -s works
configure:13663: result: yes
configure:13697: checking for egrep
configure:13765: result: /bin/grep -E
configure:13776: checking for library containing floor
configure:13806: x86_64-pc-linux-gnu-gcc -o conftest -O2 -pipe -march=x86-64 -frecord-gcc-switches -Wall  -Wl,-O1 -Wl,--as-needed -Wl,--defsym=__gentoo_check_ldflags__=0 conftest.c  >&5
conftest.c:27:6: warning: conflicting types for built-in function 'floor'; expected 'double(double)' [-Wbuiltin-declaration-mismatch]
   27 | char floor ();
      |      ^~~~~
conftest.c:1:1: note: 'floor' is declared in header '<math.h>'
    1 | /* confdefs.h */
/usr/lib/gcc/x86_64-pc-linux-gnu/11.1.0/../../../../x86_64-pc-linux-gnu/bin/ld: /var/tmp/portage/net-misc/iperf-3.10/temp/ccw0U6fp.o: in function `main':
conftest.c:(.text.startup+0x7): undefined reference to `floor'
collect2: error: ld returned 1 exit status
configure:13806: $? = 1
configure: failed program was:
| /* confdefs.h */
| #define PACKAGE_NAME "iperf"
| #define PACKAGE_TARNAME "iperf"
| #define PACKAGE_VERSION "3.10"
| #define PACKAGE_STRING "iperf 3.10"
| #define PACKAGE_BUGREPORT "https://github.com/esnet/iperf"
| #define PACKAGE_URL "https://software.es.net/iperf/"
| #define PACKAGE "iperf"
| #define VERSION "3.10"
| #define HAVE_STDIO_H 1
| #define HAVE_STDLIB_H 1
| #define HAVE_STRING_H 1
| #define HAVE_INTTYPES_H 1
| #define HAVE_STDINT_H 1
| #define HAVE_STRINGS_H 1
| #define HAVE_SYS_STAT_H 1
| #define HAVE_SYS_TYPES_H 1
| #define HAVE_UNISTD_H 1
| #define STDC_HEADERS 1
| #define HAVE_DLFCN_H 1
| #define LT_OBJDIR ".libs/"
| /* end confdefs.h.  */
| 
| /* Override any GCC internal prototype to avoid an error.
|    Use char because int might match the return type of a GCC
|    builtin and then its argument prototype would still apply.  */
| char floor ();
| int
| main (void)
| {
| return floor ();
|   ;
|   return 0;
| }
configure:13806: x86_64-pc-linux-gnu-gcc -o conftest -O2 -pipe -march=x86-64 -frecord-gcc-switches -Wall  -Wl,-O1 -Wl,--as-needed -Wl,--defsym=__gentoo_check_ldflags__=0 conftest.c -lm   >&5
conftest.c:27:6: warning: conflicting types for built-in function 'floor'; expected 'double(double)' [-Wbuiltin-declaration-mismatch]
   27 | char floor ();
      |      ^~~~~
conftest.c:1:1: note: 'floor' is declared in header '<math.h>'
    1 | /* confdefs.h */
configure:13806: $? = 0
configure:13826: result: -lm
configure:13842: checking for library containing socket
configure:13872: x86_64-pc-linux-gnu-gcc -o conftest -O2 -pipe -march=x86-64 -frecord-gcc-switches -Wall  -Wl,-O1 -Wl,--as-needed -Wl,--defsym=__gentoo_check_ldflags__=0 conftest.c -lm  >&5
configure:13872: $? = 0
configure:13892: result: none required
configure:13908: checking for library containing inet_ntop
configure:13938: x86_64-pc-linux-gnu-gcc -o conftest -O2 -pipe -march=x86-64 -frecord-gcc-switches -Wall  -Wl,-O1 -Wl,--as-needed -Wl,--defsym=__gentoo_check_ldflags__=0 conftest.c -lm  >&5
configure:13938: $? = 0
configure:13958: result: none required
configure:13974: checking for an ANSI C-conforming const
configure:14041: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches -Wall  conftest.c >&5
configure:14041: $? = 0
configure:14049: result: yes
configure:14059: checking for poll.h
configure:14059: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches -Wall  conftest.c >&5
configure:14059: $? = 0
configure:14059: result: yes
configure:14094: checking for linux/tcp.h
configure:14094: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches -Wall  conftest.c >&5
configure:14094: $? = 0
configure:14094: result: yes
configure:14104: checking for sys/socket.h
configure:14104: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches -Wall  conftest.c >&5
configure:14104: $? = 0
configure:14104: result: yes
configure:14113: checking for netinet/sctp.h
configure:14113: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches -Wall  conftest.c >&5
conftest.c:31:10: fatal error: netinet/sctp.h: No such file or directory
   31 | #include <netinet/sctp.h>
      |          ^~~~~~~~~~~~~~~~
compilation terminated.
configure:14113: $? = 1
configure: failed program was:
| /* confdefs.h */
| #define PACKAGE_NAME "iperf"
| #define PACKAGE_TARNAME "iperf"
| #define PACKAGE_VERSION "3.10"
| #define PACKAGE_STRING "iperf 3.10"
| #define PACKAGE_BUGREPORT "https://github.com/esnet/iperf"
| #define PACKAGE_URL "https://software.es.net/iperf/"
| #define PACKAGE "iperf"
| #define VERSION "3.10"
| #define HAVE_STDIO_H 1
| #define HAVE_STDLIB_H 1
| #define HAVE_STRING_H 1
| #define HAVE_INTTYPES_H 1
| #define HAVE_STDINT_H 1
| #define HAVE_STRINGS_H 1
| #define HAVE_SYS_STAT_H 1
| #define HAVE_SYS_TYPES_H 1
| #define HAVE_UNISTD_H 1
| #define STDC_HEADERS 1
| #define HAVE_DLFCN_H 1
| #define LT_OBJDIR ".libs/"
| #define HAVE_POLL_H 1
| #define HAVE_LINUX_TCP_H 1
| #define HAVE_SYS_SOCKET_H 1
| /* end confdefs.h.  */
| #ifdef HAVE_SYS_SOCKET_H
| #include <sys/socket.h>
| #endif
| 
| 
| #include <netinet/sctp.h>
configure:14113: result: no
configure:14255: checking for endian.h
configure:14255: x86_64-pc-linux-gnu-gcc -c -O2 -pipe -march=x86-64 -frecord-gcc-switches -Wall  conftest.c >&5
configure:14255: $? = 0
configure:14255: result: yes
configure:14306: checking for x86_64-pc-linux-gnu-pkg-config
configure:14327: found /usr/bin/x86_64-pc-linux-gnu-pkg-config
configure:14338: result: x86_64-pc-linux-gnu-pkg-config
configure:14453: checking whether compiling and linking against OpenSSL works
Trying link with OPENSSL_LDFLAGS=; OPENSSL_LIBS=-lssl -lcrypto; OPENSSL_INCLUDES=
configure:14475: x86_64-pc-linux-gnu-gcc -o conftest -O2 -pipe -march=x86-64 -frecord-gcc-switches -Wall   -Wl,-O1 -Wl,--as-needed -Wl,--defsym=__gentoo_check_ldflags__=0  conftest.c -lssl -lcrypto -lm  >&5
configure:14475: $? = 0
configure:14478: result: yes
configure:14521: checking TCP_CONGESTION socket option
configure:14533: checking how to run the C preprocessor
configure:14639: result: x86_64-pc-linux-gnu-gcc -E
configure:14686: error: in `/var/tmp/portage/net-misc/iperf-3.10/work/iperf-3.10':
configure:14688: error: C preprocessor "x86_64-pc-linux-gnu-gcc -E" fails sanity check
See `config.log' for more details

## ---------------- ##
## Cache variables. ##
## ---------------- ##

ac_cv_build=x86_64-pc-linux-gnu
ac_cv_c_compiler_gnu=yes
ac_cv_c_const=yes
ac_cv_env_CC_set=set
ac_cv_env_CC_value=x86_64-pc-linux-gnu-gcc
ac_cv_env_CFLAGS_set=set
ac_cv_env_CFLAGS_value='-O2 -pipe -march=x86-64 -frecord-gcc-switches'
ac_cv_env_CPPFLAGS_set=
ac_cv_env_CPPFLAGS_value=
ac_cv_env_CPP_set=set
ac_cv_env_CPP_value='x86_64-pc-linux-gnu-gcc -E'
ac_cv_env_LDFLAGS_set=set
ac_cv_env_LDFLAGS_value='-Wl,-O1 -Wl,--as-needed -Wl,--defsym=__gentoo_check_ldflags__=0'
ac_cv_env_LIBS_set=
ac_cv_env_LIBS_value=
ac_cv_env_LT_SYS_LIBRARY_PATH_set=
ac_cv_env_LT_SYS_LIBRARY_PATH_value=
ac_cv_env_build_alias_set=set
ac_cv_env_build_alias_value=x86_64-pc-linux-gnu
ac_cv_env_host_alias_set=set
ac_cv_env_host_alias_value=x86_64-pc-linux-gnu
ac_cv_env_target_alias_set=
ac_cv_env_target_alias_value=
ac_cv_header_dlfcn_h=yes
ac_cv_header_endian_h=yes
ac_cv_header_inttypes_h=yes
ac_cv_header_linux_tcp_h=yes
ac_cv_header_netinet_sctp_h=no
ac_cv_header_poll_h=yes
ac_cv_header_stdint_h=yes
ac_cv_header_stdio_h=yes
ac_cv_header_stdlib_h=yes
ac_cv_header_string_h=yes
ac_cv_header_strings_h=yes
ac_cv_header_sys_socket_h=yes
ac_cv_header_sys_stat_h=yes
ac_cv_header_sys_types_h=yes
ac_cv_header_unistd_h=yes
ac_cv_host=x86_64-pc-linux-gnu
ac_cv_objext=o
ac_cv_path_EGREP='/bin/grep -E'
ac_cv_path_FGREP='/bin/grep -F'
ac_cv_path_GREP=/bin/grep
ac_cv_path_SED=/bin/sed
ac_cv_path_install='/usr/lib/portage/python3.9/ebuild-helpers/xattr/install -c'
ac_cv_path_lt_DD=/bin/dd
ac_cv_path_mkdir=/bin/mkdir
ac_cv_prog_AR=x86_64-pc-linux-gnu-ar
ac_cv_prog_AWK=gawk
ac_cv_prog_CC=x86_64-pc-linux-gnu-gcc
ac_cv_prog_CPP='x86_64-pc-linux-gnu-gcc -E'
ac_cv_prog_OBJDUMP=x86_64-pc-linux-gnu-objdump
ac_cv_prog_PKG_CONFIG=x86_64-pc-linux-gnu-pkg-config
ac_cv_prog_RANLIB=x86_64-pc-linux-gnu-ranlib
ac_cv_prog_STRIP=x86_64-pc-linux-gnu-strip
ac_cv_prog_cc_c11=
ac_cv_prog_cc_g=yes
ac_cv_prog_cc_stdc=
ac_cv_prog_make_make_set=yes
ac_cv_search_floor=-lm
ac_cv_search_inet_ntop='none required'
ac_cv_search_socket='none required'
am_cv_CC_dependencies_compiler_type=none
am_cv_make_support_nested_variables=yes
am_cv_prog_cc_c_o=yes
lt_cv_ar_at_file=@
lt_cv_archive_cmds_need_lc=no
lt_cv_deplibs_check_method=pass_all
lt_cv_file_magic_cmd='$MAGIC_CMD'
lt_cv_file_magic_test_file=
lt_cv_ld_reload_flag=-r
lt_cv_nm_interface='BSD nm'
lt_cv_objdir=.libs
lt_cv_path_LD=x86_64-pc-linux-gnu-ld
lt_cv_path_NM=x86_64-pc-linux-gnu-nm
lt_cv_path_mainfest_tool=no
lt_cv_prog_compiler_c_o=yes
lt_cv_prog_compiler_pic='-fPIC -DPIC'
lt_cv_prog_compiler_pic_works=yes
lt_cv_prog_compiler_rtti_exceptions=no
lt_cv_prog_compiler_static_works=yes
lt_cv_prog_gnu_ld=yes
lt_cv_sharedlib_from_linklib_cmd='printf %s\n'
lt_cv_shlibpath_overrides_runpath=yes
lt_cv_sys_global_symbol_pipe='sed -n -e '\''s/^.*[	 ]\([ABCDGIRSTW][ABCDGIRSTW]*\)[	 ][	 ]*\([_A-Za-z][_A-Za-z0-9]*\)$/\1 \2 \2/p'\'' | sed '\''/ __gnu_lto/d'\'''
lt_cv_sys_global_symbol_to_c_name_address='sed -n -e '\''s/^: \(.*\) .*$/  {"\1", (void *) 0},/p'\'' -e '\''s/^[ABCDGIRSTW][ABCDGIRSTW]* .* \(.*\)$/  {"\1", (void *) \&\1},/p'\'''
lt_cv_sys_global_symbol_to_c_name_address_lib_prefix='sed -n -e '\''s/^: \(.*\) .*$/  {"\1", (void *) 0},/p'\'' -e '\''s/^[ABCDGIRSTW][ABCDGIRSTW]* .* \(lib.*\)$/  {"\1", (void *) \&\1},/p'\'' -e '\''s/^[ABCDGIRSTW][ABCDGIRSTW]* .* \(.*\)$/  {"lib\1", (void *) \&\1},/p'\'''
lt_cv_sys_global_symbol_to_cdecl='sed -n -e '\''s/^T .* \(.*\)$/extern int \1();/p'\'' -e '\''s/^[ABCDGIRSTW][ABCDGIRSTW]* .* \(.*\)$/extern char \1;/p'\'''
lt_cv_sys_global_symbol_to_import=
lt_cv_sys_max_cmd_len=1572864
lt_cv_to_host_file_cmd=func_convert_file_noop
lt_cv_to_tool_file_cmd=func_convert_file_noop
lt_cv_truncate_bin='/bin/dd bs=4096 count=1'

## ----------------- ##
## Output variables. ##
## ----------------- ##

ACLOCAL='${SHELL} '\''/var/tmp/portage/net-misc/iperf-3.10/work/iperf-3.10/config/missing'\'' aclocal-1.16'
AMDEPBACKSLASH=''
AMDEP_FALSE=''
AMDEP_TRUE='#'
AMTAR='$${TAR-tar}'
AM_BACKSLASH='\'
AM_DEFAULT_V='$(AM_DEFAULT_VERBOSITY)'
AM_DEFAULT_VERBOSITY='1'
AM_V='$(V)'
AR='x86_64-pc-linux-gnu-ar'
AUTOCONF='${SHELL} '\''/var/tmp/portage/net-misc/iperf-3.10/work/iperf-3.10/config/missing'\'' autoconf'
AUTOHEADER='${SHELL} '\''/var/tmp/portage/net-misc/iperf-3.10/work/iperf-3.10/config/missing'\'' autoheader'
AUTOMAKE='${SHELL} '\''/var/tmp/portage/net-misc/iperf-3.10/work/iperf-3.10/config/missing'\'' automake-1.16'
AWK='gawk'
CC='x86_64-pc-linux-gnu-gcc'
CCDEPMODE='depmode=none'
CFLAGS='-O2 -pipe -march=x86-64 -frecord-gcc-switches -Wall'
CPP='x86_64-pc-linux-gnu-gcc -E'
CPPFLAGS=' '
CYGPATH_W='echo'
DEFS=''
DEPDIR='.deps'
DLLTOOL='false'
DSYMUTIL=''
DUMPBIN=''
ECHO_C=''
ECHO_N='-n'
ECHO_T=''
EGREP='/bin/grep -E'
ENABLE_PROFILING_FALSE=''
ENABLE_PROFILING_TRUE='#'
ENABLE_STATIC_BIN_FALSE=''
ENABLE_STATIC_BIN_TRUE='#'
EXEEXT=''
FGREP='/bin/grep -F'
GREP='/bin/grep'
INSTALL_DATA='${INSTALL} -m 644'
INSTALL_PROGRAM='${INSTALL}'
INSTALL_SCRIPT='${INSTALL}'
INSTALL_STRIP_PROGRAM='$(install_sh) -c -s'
LD='x86_64-pc-linux-gnu-ld -m elf_x86_64'
LDFLAGS='-Wl,-O1 -Wl,--as-needed -Wl,--defsym=__gentoo_check_ldflags__=0 '
LIBOBJS=''
LIBS='-lssl -lcrypto -lm '
LIBTOOL='$(SHELL) $(top_builddir)/libtool'
LIPO=''
LN_S='ln -s'
LTLIBOBJS=''
LT_SYS_LIBRARY_PATH=''
MAINT='#'
MAINTAINER_MODE_FALSE=''
MAINTAINER_MODE_TRUE='#'
MAKEINFO='${SHELL} '\''/var/tmp/portage/net-misc/iperf-3.10/work/iperf-3.10/config/missing'\'' makeinfo'
MANIFEST_TOOL=':'
MKDIR_P='/bin/mkdir -p'
NM='x86_64-pc-linux-gnu-nm'
NMEDIT=''
OBJDUMP='x86_64-pc-linux-gnu-objdump'
OBJEXT='o'
OPENSSL_INCLUDES=''
OPENSSL_LDFLAGS=''
OPENSSL_LIBS='-lssl -lcrypto'
OTOOL64=''
OTOOL=''
PACKAGE='iperf'
PACKAGE_BUGREPORT='https://github.com/esnet/iperf'
PACKAGE_NAME='iperf'
PACKAGE_STRING='iperf 3.10'
PACKAGE_TARNAME='iperf'
PACKAGE_URL='https://software.es.net/iperf/'
PACKAGE_VERSION='3.10'
PATH_SEPARATOR=':'
PKG_CONFIG='x86_64-pc-linux-gnu-pkg-config'
RANLIB='x86_64-pc-linux-gnu-ranlib'
SED='/bin/sed'
SET_MAKE=''
SHELL='/bin/sh'
STRIP='x86_64-pc-linux-gnu-strip'
VERSION='3.10'
ac_ct_AR=''
ac_ct_CC=''
ac_ct_DUMPBIN=''
am__EXEEXT_FALSE=''
am__EXEEXT_TRUE=''
am__fastdepCC_FALSE=''
am__fastdepCC_TRUE='#'
am__include='include'
am__isrc=''
am__leading_dot='.'
am__nodep=''
am__quote=''
am__tar='$${TAR-tar} chof - "$$tardir"'
am__untar='$${TAR-tar} xf -'
bindir='${exec_prefix}/bin'
build='x86_64-pc-linux-gnu'
build_alias='x86_64-pc-linux-gnu'
build_cpu='x86_64'
build_os='linux-gnu'
build_vendor='pc'
datadir='/usr/share'
datarootdir='${prefix}/share'
docdir='/usr/share/doc/iperf-3.10'
dvidir='${docdir}'
exec_prefix='NONE'
host='x86_64-pc-linux-gnu'
host_alias='x86_64-pc-linux-gnu'
host_cpu='x86_64'
host_os='linux-gnu'
host_vendor='pc'
htmldir='/usr/share/doc/iperf-3.10/html'
includedir='${prefix}/include'
infodir='/usr/share/info'
install_sh='${SHELL} /var/tmp/portage/net-misc/iperf-3.10/work/iperf-3.10/config/install-sh'
libdir='/usr/lib64'
libexecdir='${exec_prefix}/libexec'
localedir='${datarootdir}/locale'
localstatedir='/var/lib'
mandir='/usr/share/man'
mkdir_p='$(MKDIR_P)'
oldincludedir='/usr/include'
pdfdir='${docdir}'
prefix='/usr'
program_transform_name='s,x,x,'
psdir='${docdir}'
runstatedir='${localstatedir}/run'
sbindir='${exec_prefix}/sbin'
sharedstatedir='${prefix}/com'
sysconfdir='/etc'
target_alias=''

## ----------- ##
## confdefs.h. ##
## ----------- ##

/* confdefs.h */
#define PACKAGE_NAME "iperf"
#define PACKAGE_TARNAME "iperf"
#define PACKAGE_VERSION "3.10"
#define PACKAGE_STRING "iperf 3.10"
#define PACKAGE_BUGREPORT "https://github.com/esnet/iperf"
#define PACKAGE_URL "https://software.es.net/iperf/"
#define PACKAGE "iperf"
#define VERSION "3.10"
#define HAVE_STDIO_H 1
#define HAVE_STDLIB_H 1
#define HAVE_STRING_H 1
#define HAVE_INTTYPES_H 1
#define HAVE_STDINT_H 1
#define HAVE_STRINGS_H 1
#define HAVE_SYS_STAT_H 1
#define HAVE_SYS_TYPES_H 1
#define HAVE_UNISTD_H 1
#define STDC_HEADERS 1
#define HAVE_DLFCN_H 1
#define LT_OBJDIR ".libs/"
#define HAVE_POLL_H 1
#define HAVE_LINUX_TCP_H 1
#define HAVE_SYS_SOCKET_H 1
#define HAVE_ENDIAN_H 1
#define HAVE_SSL 1

configure: exit 1