Created attachment 437254 [details] build.log dev-lang/perl fails to build with gcc-6.1 (gcc-4.9.3 is ok) on musl profiles and at least the arm architecture. See attached build.log. Portage 2.2.28 (python 2.7.11-final-0, hardened/linux/musl/arm/armv7a, gcc-6.1.0, musl-1.1.14-r1, 4.6.0-rc6-00001-gcdfa89d-dirty armv7l) ================================================================= System uname: Linux-4.6.0-rc6-00001-gcdfa89d-dirty-armv7l-with-gentoo-2.2 KiB Mem: 2034892 total, 1079136 free KiB Swap: 0 total, 0 free sh bash 4.3_p42-r1 ld GNU ld (Gentoo 2.25.1 p1.1) 2.25.1 app-shells/bash: 4.3_p42-r1::gentoo dev-lang/perl: 5.20.2::gentoo dev-lang/python: 2.7.11-r2::gentoo, 3.4.3-r7::gentoo dev-util/cmake: 3.3.1-r1::gentoo sys-apps/baselayout: 2.2::gentoo sys-apps/openrc: 0.19.1::gentoo sys-apps/sandbox: 2.10-r99::musl sys-devel/autoconf: 2.13::gentoo, 2.69::gentoo sys-devel/automake: 1.11.6-r1::gentoo, 1.13.4::gentoo, 1.14.1::gentoo, 1.15::gentoo sys-devel/binutils: 2.25.1-r1::gentoo sys-devel/gcc: 4.9.3-r99::musl, 6.1.0::musl sys-devel/gcc-config: 1.7.3::gentoo sys-devel/libtool: 2.4.6::gentoo sys-devel/make: 4.1-r1::gentoo sys-kernel/linux-headers: 4.3-r99::musl (virtual/os-headers) sys-libs/musl: 1.1.14-r1::gentoo Repositories: tox-overlay location: /var/lib/layman/gentoo-overlay-tox sync-type: git sync-uri: https://github.com/Tox/gentoo-overlay-tox.git masters: gentoo priority: 2 gentoo location: /usr/portage sync-type: git sync-uri: https://github.com/gentoo/gentoo.git priority: 5 musl location: /home/felix/Downloads/gentoo-musl sync-type: git sync-uri: https://anongit.gentoo.org/git/proj/musl.git masters: gentoo priority: 8 local location: /home/felix/.usr/portage masters: gentoo priority: 10 ACCEPT_KEYWORDS="arm" ACCEPT_LICENSE="* -@EULA" CBUILD="armv7a-hardfloat-linux-musleabi" CFLAGS="-O2 -pipe -march=armv7-a -mfloat-abi=hard" CHOST="armv7a-hardfloat-linux-musleabi" CONFIG_PROTECT="/etc" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo /etc/texmf/language.dat.d /etc/texmf/language.def.d /etc/texmf/updmap.d /etc/texmf/web2c" CXXFLAGS="-O2 -pipe -fomit-frame-pointer" DISTDIR="/usr/portage/distfiles" FCFLAGS="-O2 -pipe -march=armv7-a -mfpu=vfpv3-d16 -mfloat-abi=hard" FEATURES="assume-digests binpkg-logs collision-protect config-protect-if-modified distlocks ebuild-locks fixlafiles merge-sync news parallel-fetch preserve-libs protect-owned sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync xattr" FFLAGS="-O2 -pipe -march=armv7-a -mfpu=vfpv3-d16 -mfloat-abi=hard" GENTOO_MIRRORS="http://ftp.uni-erlangen.de/pub/mirrors/gentoo http://mirror.switch.ch/ftp/mirror/gentoo" INSTALL_MASK="charset.alias /etc/init.d /etc/conf.d /etc/runit /etc/runlevels /usr/lib/systemd /usr/share/locale /usr/share/doc /usr/share/gtk-doc /usr/share/applications" LANG="en_US.UTF-8" LDFLAGS="-Wl,-O1 -Wl,--as-needed" MAKEOPTS="-j5" PKGDIR="/usr/portage/packages" PORTAGE_CONFIGROOT="/" PORTAGE_RSYNC_EXTRA_OPTS="--exclude-from=/etc/portage/portage.exclude" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --omit-dir-times --compress --force --whole-file --delete --stats --human-readable --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages --exclude=/.git" PORTAGE_TMPDIR="/var/tmp" USE="arm armv7l cli cracklib crypt cxx dri fortran hardened iconv libressl minimal modules nptl openmp pax_kernel pcre pic readline seccomp session ssl tcpd threads unicode xattr zlib" APACHE2_MODULES="authn_core authz_core socache_shmcb unixd actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" CALLIGRA_FEATURES="kexi words flow plan sheets stage tables krita karbon braindump author" CAMERAS="ptp2" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" ELIBC="musl" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf superstar2 timing tsip tripmate tnt ublox ubx" INPUT_DEVICES="evdev" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php5-5" PYTHON_SINGLE_TARGET="python2_7" PYTHON_TARGETS="python2_7 python3_4" QEMU_USER_TARGETS="i386 m68k sparc x86_64" RUBY_TARGETS="ruby20 ruby21" SANE_BACKENDS="net" USERLAND="GNU" VIDEO_CARDS="fbdev nouveau" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq steal rawnat logmark ipmark dhcpmac delude chaos account" Unset: CC, CPPFLAGS, CTARGET, CXX, EMERGE_DEFAULT_OPTS, LC_ALL, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, USE_PYTHON
Created attachment 437256 [details, diff] Patch for perl-5.22 After some debugging it seems that the code violates the strict aliasing rules (gv and *svp are of different types but point to the same memory.) so that gcc is allowed to do some optimization leading to the reference counter being just decremented instead of incremented and subsequently decremented. This hacky patch makes perl compile for me. The relevant code is still identical in perl git. I wonder why noone else seems to have hit this.
With perl-2.24.0-r1 the patch no longer seems necessary.
Actually I cannot reproduce this bug at all with in tree gcc-6.2.0. perl is supposed to build with -fno-strict-aliasing when non-acient gcc is detected. For some reason, the compiler I've used before was not correctly detected by perl's Configure script.
