While attempting to track down *another* unrelated issue, I needed to build a debuggable MySQL. ATtempts end with this: [ 3%] Building C object strings/CMakeFiles/strings.dir/ctype-ucs2.c.o cd /var/tmp/portage/dev-db/mysql-5.5.32/work/mysql-5.5.32_build/strings && /usr/bin/x86_64-pc-linux-gnu-gcc -DDISABLE_MYSQL_THREAD_H -DHAVE_CONFIG_H -O2 -pipe -fno-strict-aliasing -fPIC -Wall -Wall -Wextra -Wunused -Wwrite-strings -Wno-strict-aliasing -Werror -Wdeclaration-after-statement -O2 -g -DNDEBUG -DDBUG_OFF -I/var/tmp/portage/dev-db/mysql-5.5.32/work/mysql-5.5.32_build/include -I/var/tmp/portage/dev-db/mysql-5.5.32/work/mysql/include -o CMakeFiles/strings.dir/ctype-ucs2.c.o -c /var/tmp/portage/dev-db/mysql-5.5.32/work/mysql/strings/ctype-ucs2.c /var/tmp/portage/dev-db/mysql-5.5.32/work/mysql/strings/ctype-ucs2.c: In function 'my_fill_utf32': /var/tmp/portage/dev-db/mysql-5.5.32/work/mysql/strings/ctype-ucs2.c:2321:8: error: variable 'buflen' set but not used [-Werror=unused-but-set-variable] cc1: all warnings being treated as errors make[2]: *** [strings/CMakeFiles/strings.dir/ctype-ucs2.c.o] Error 1 make[2]: Leaving directory `/var/tmp/portage/dev-db/mysql-5.5.32/work/mysql-5.5.32_build' make[1]: *** [strings/CMakeFiles/strings.dir/all] Error 2 make[1]: Leaving directory `/var/tmp/portage/dev-db/mysql-5.5.32/work/mysql-5.5.32_build' make: *** [all] Error 2 Note that negation of make options, C and LDFLAG options don't change the answer. Attempts to find a documented MySQL bug haven't been very fruitful. Reproducible: Always Steps to Reproduce: 1. Build dev-db/mysql-5.5.32 with USE="debug" 2. watch it fail 3. cry Actual Results: [ 3%] Building C object strings/CMakeFiles/strings.dir/ctype-ucs2.c.o cd /var/tmp/portage/dev-db/mysql-5.5.32/work/mysql-5.5.32_build/strings && /usr/bin/x86_64-pc-linux-gnu-gcc -DDISABLE_MYSQL_THREAD_H -DHAVE_CONFIG_H -O2 -pipe -fno-strict-aliasing -fPIC -Wall -Wall -Wextra -Wunused -Wwrite-strings -Wno-strict-aliasing -Werror -Wdeclaration-after-statement -O2 -g -DNDEBUG -DDBUG_OFF -I/var/tmp/portage/dev-db/mysql-5.5.32/work/mysql-5.5.32_build/include -I/var/tmp/portage/dev-db/mysql-5.5.32/work/mysql/include -o CMakeFiles/strings.dir/ctype-ucs2.c.o -c /var/tmp/portage/dev-db/mysql-5.5.32/work/mysql/strings/ctype-ucs2.c /var/tmp/portage/dev-db/mysql-5.5.32/work/mysql/strings/ctype-ucs2.c: In function 'my_fill_utf32': /var/tmp/portage/dev-db/mysql-5.5.32/work/mysql/strings/ctype-ucs2.c:2321:8: error: variable 'buflen' set but not used [-Werror=unused-but-set-variable] cc1: all warnings being treated as errors make[2]: *** [strings/CMakeFiles/strings.dir/ctype-ucs2.c.o] Error 1 make[2]: Leaving directory `/var/tmp/portage/dev-db/mysql-5.5.32/work/mysql-5.5.32_build' make[1]: *** [strings/CMakeFiles/strings.dir/all] Error 2 make[1]: Leaving directory `/var/tmp/portage/dev-db/mysql-5.5.32/work/mysql-5.5.32_build' make: *** [all] Error 2 Expected Results: not that emerge --info Portage 2.1.11.55 (hardened/linux/amd64, gcc-4.6.3, glibc-2.16.0, 3.9.4-hardened-r2 x86_64) ================================================================= System uname: Linux-3.9.4-hardened-r2-x86_64-AMD_Opteron-tm-_Processor_6128-with-gentoo-2.2 KiB Mem: 16465532 total, 361928 free KiB Swap: 8388604 total, 8216468 free Timestamp of tree: Wed, 11 Dec 2013 21:45:01 +0000 ld GNU ld (GNU Binutils) 2.23.1 ccache version 3.1.9 [disabled] app-shells/bash: 4.2_p42 dev-lang/python: 2.7.3-r3, 3.2.3-r2 dev-util/ccache: 3.1.9 dev-util/cmake: 2.8.10.2-r1 dev-util/pkgconfig: 0.28 sys-apps/baselayout: 2.2 sys-apps/openrc: 0.11.8 sys-apps/sandbox: 2.6 sys-devel/autoconf: 2.69 sys-devel/automake: 1.11.6, 1.12.6, 1.13.1 sys-devel/binutils: 2.23.1 sys-devel/gcc: 4.6.3, 4.7.2-r1 sys-devel/gcc-config: 1.8 sys-devel/libtool: 2.4.2 sys-devel/make: 3.82-r4 sys-kernel/linux-headers: 3.8 (virtual/os-headers) sys-libs/glibc: 2.16.0 Repositories: gentoo pentoo poly-c ACCEPT_KEYWORDS="amd64 ~amd64" ACCEPT_LICENSE="*" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-march=amdfam10 -O2 -pipe -fomit-frame-pointer" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /etc/pam.d/ /var/bind /var/spool/munin-async/.ssh" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/php/apache2-php5.4/ext-active/ /etc/php/cgi-php5.4/ext-active/ /etc/php/cli-php5.4/ext-active/ /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo" CXXFLAGS="-march=amdfam10 -O2 -pipe -fomit-frame-pointer" DISTDIR="/usr/portage/distfiles" FCFLAGS="-O2 -pipe" FEATURES="assume-digests binpkg-logs config-protect-if-modified distlocks ebuild-locks fixlafiles merge-sync metadata-transfer news parallel-fetch protect-owned sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch" FFLAGS="-O2 -pipe" GENTOO_MIRRORS="http://gentoo.osuosl.org" LDFLAGS="-Wl,--hash-style=gnu,-O1 -Wl,--as-needed" MAKEOPTS="-j8" PKGDIR="/usr/portage/packages" PORTAGE_CONFIGROOT="/" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --stats --human-readable --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" PORTDIR_OVERLAY="/var/lib/layman/pentoo /var/lib/layman/poly-c" SYNC="rsync://rsync.gtlib.gatech.edu/gentoo-portage" USE="3dnow amd64 cups custom-cflags custom-optimization cxx fuse hardened hvm ipv6 lm_sensors logrotate mmx mmxext multilib ncurses offensive openrc openssl pax_kernel pcre qemu readline snmp spell sse sse2 ssl threads unicode zlib" ABI_X86="64" APACHE2_MODULES="authz_host dir mime userdir vhost_alias alias rewrite log_config" CURL_SSL="openssl" ELIBC="glibc" GRUB_PLATFORMS="pc" INPUT_DEVICES="keyboard mouse synaptics" KERNEL="linux" LINGUAS="en_US en" NGINX_MODULES_HTTP="auth_basic access autoindex browser empty_gif geoip gzip memcached perl proxy realip rewrite scgi stub_status upload upload_progress fastcgi" NGINX_MODULES_MAIL="*" PYTHON_SINGLE_TARGET="python2_7" PYTHON_TARGETS="python2_7" USERLAND="GNU" Unset: CPPFLAGS, CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LANG, LC_ALL, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, USE_PYTHON make.conf CFLAGS="-march=amdfam10 -O2 -pipe -fomit-frame-pointer"# -floop-interchange -floop-strip-mine -floop-block" CXXFLAGS="${CFLAGS}" LDFLAGS="-Wl,--hash-style=gnu,-O1 -Wl,--as-needed" ACCEPT_KEYWORDS=~amd64 # WARNING: Changing your CHOST is not something that should be done lightly. # Please consult http://www.gentoo.org/doc/en/change-chost.xml before changing. CHOST="x86_64-pc-linux-gnu" DISTDIR="/usr/portage/distfiles" CONFIG_PROTECT="/etc/pam.d/" # These are the USE flags that were used in addition to what is provided by the # profile used for building. GRUB_PLATFORMS="pc" USE="-* openssl cups qemu hvm cxx hardened custom-cflags custom-optimization ssl fuse spell mmx sse \ sse2 mmxext 3dnow ipv6 logrotate readline unicode threads \ offensive ncurses lm_sensors snmp pcre zlib pax_kernel ipv6 openrc" APACHE2_MODULES="authz_host dir mime userdir vhost_alias alias rewrite log_config" NGINX_MODULES_HTTP="auth_basic access autoindex browser empty_gif geoip gzip memcached perl proxy realip rewrite scgi stub_status upload upload_progress fastcgi" NGINX_MODULES_MAIL="*" FEATURES="parallel-fetch metadata-transfer" MAKEOPTS="-j8" INPUT_DEVICES="keyboard mouse synaptics" GENTOO_MIRRORS="http://gentoo.osuosl.org" #SYNC="rsync://rsync.us.gentoo.org/gentoo-portage" SYNC="rsync://rsync.gtlib.gatech.edu/gentoo-portage" LINGUAS="en_US en" source /var/lib/layman/make.conf PORTAGE_ECLASS_WARNING_ENABLE=0 PORTAGE_REPO_DUPLICATE_WARN=0 ACCEPT_LICENSE=* HTTPD_USER="nginx" HTTPD_GROUP="nginx" CURL_SSL="openssl" PYTHON_SINGLE_TARGET="python2_7" PYTHON_TARGETS="python2_7"
Created attachment 365402 [details] build.log
Build failures confirmed on 5.6.15 and 5.5.35 The relevant code bloc in ctype-ucs2.c is thus: static void my_fill_utf32(CHARSET_INFO *cs, char *s, size_t slen, int fill) { char buf[10]; uint buflen; char *e= s + slen; DBUG_ASSERT((slen % 4) == 0); buflen= cs->cset->wc_mb(cs, (my_wc_t) fill, (uchar*) buf, (uchar*) buf + sizeof(buf)); DBUG_ASSERT(buflen == 4); while (s < e) { memcpy(s, buf, 4); s+= 4; } } The problem appears that one of the default GCC CFLAGS (at least in GCC 4.6 and 4.7) is that -Werror=unused-but-set-variable is a default. So this unused buflen variable in the codebloc is causing the failure. Disabling that check with the CFLAG addition of -Wno-unused-but-set-variable allows the build to nearly complete in 5.5 and 5.6, though now build failure happens in different spots for different reasons. Is this a pecularity of my environment, or does nobody build a debuggable MySQL?
The journey continues. It appears that the overall problem (I use the word lightly) is that the build environment defaults to -Werror. When MySQL is built with the debug flag (manually via cmake -DWITH_DEBUG=1), certain code paths that aren't normally used spew a few warnings which are being treated as errors. Building with -Wno-error explicitly set manually in CMakeCache.txt allowed the build to complete with no issues. Now that I grasp what's going on, the two things which really irk me is that this was never noticed (as far as I can tell) and that the MySQL build environment is using cflags that I never specified. What's not clear is what has to happen to fix this. This *looks* like an upstream MySQL failure to me, so should it be reported to them? Or is this a gentoo-ism?
The proper fix is to completely remove -Werror as outlined in http://devmanual.gentoo.org/ebuild-writing/common-mistakes/index.html under "-Werror compiler flag not removed" --- a/cmake/maintainer.cmake +++ b/cmake/maintainer.cmake @@ -18,7 +18,7 @@ # Setup GCC (GNU C compiler) warning options. MACRO(SET_MYSQL_MAINTAINER_GNU_C_OPTIONS) SET(MY_MAINTAINER_WARNINGS - "-Wall -Wextra -Wunused -Wwrite-strings -Wno-strict-aliasing -Werror") + "-Wall -Wextra -Wunused -Wwrite-strings -Wno-strict-aliasing") CHECK_C_COMPILER_FLAG("-Wdeclaration-after-statement" HAVE_DECLARATION_AFTER_STATEMENT) IF(HAVE_DECLARATION_AFTER_STATEMENT)
Patch added to mysql-extras along with a 5.6 patch
I just added the patch to src_prepare, because such build failures are not acceptable. Don't forget to remove src_prepare phase when you bump MY_EXTRAS_VER.
Closing this bug as we've pushed the work from the overlay into the tree.
