This package currently fails to build (at least on the amd64 architecture) with link time optimizations enabled. For a background for LTO please see https://wiki.debian.org/ToolChain/LTO The goal is to enable this optimization by default in an upcoming Debian release in dpkg-buildflags for 64bit architectures. The goal is to get this package to build with link time optimizations, or to explicitly disable link time optimizations for this package build. To reproduce the build failure, enable the lto optimization in testing/unstable by adding "optimize=+lto" to DEB_BUILD_MAINT_OPTIONS in the debian/rules file, or if this macro is unset, just set it: export DEB_BUILD_MAINT_OPTIONS = optimize=+lto Please try to fix the build with lto enabled, fixing the packaging or forwarding the issue upstream. If the issue cannot be fixed, explicitly disallow building the package with lto by adding to your rules file: export DEB_BUILD_MAINT_OPTIONS = optimize=-lto or adding that string to your existing setting of DEB_BUILD_MAINT_OPTIONS. The full build log can be found at: http://qa-logs.debian.net/2022/06/09/dpkglto/tua_4.3-14_unstable_dpkglto.log The last lines of the build log are at the end of this report. [...] 398 | fscanf (pcd_file, "%lf", &yylval.fval); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ gcc -c -DLOCALEDIR=\"/usr/share/locale\" -DHAVE_CONFIG_H -DLIBDIR=\"/etc\" -I. -I.. -I../intl -I../intl -Wdate-time -D_FORTIFY_SOURCE=2 -g -O2 -ffile-prefix-map=/<<PKGBUILDDIR>>=. -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -Wall phonesw.c gcc -c -DLOCALEDIR=\"/usr/share/locale\" -DHAVE_CONFIG_H -DLIBDIR=\"/etc\" -I. -I.. -I../intl -I../intl -Wdate-time -D_FORTIFY_SOURCE=2 -g -O2 -ffile-prefix-map=/<<PKGBUILDDIR>>=. -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -Wall portalias.c gcc -c -DLOCALEDIR=\"/usr/share/locale\" -DHAVE_CONFIG_H -DLIBDIR=\"/etc\" -I. -I.. -I../intl -I../intl -Wdate-time -D_FORTIFY_SOURCE=2 -g -O2 -ffile-prefix-map=/<<PKGBUILDDIR>>=. -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -Wall porttree.c gcc -c -DLOCALEDIR=\"/usr/share/locale\" -DHAVE_CONFIG_H -DLIBDIR=\"/etc\" -I. -I.. -I../intl -I../intl -Wdate-time -D_FORTIFY_SOURCE=2 -g -O2 -ffile-prefix-map=/<<PKGBUILDDIR>>=. -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -Wall process.c gcc -c -DLOCALEDIR=\"/usr/share/locale\" -DHAVE_CONFIG_H -DLIBDIR=\"/etc\" -I. -I.. -I../intl -I../intl -Wdate-time -D_FORTIFY_SOURCE=2 -g -O2 -ffile-prefix-map=/<<PKGBUILDDIR>>=. -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -Wall prochist.c In file included from /usr/include/string.h:519, from tua.h:40, from prochist.c:24: In function ‘strncpy’, inlined from ‘ReadALine’ at prochist.c:58:3, inlined from ‘read_system_history’ at prochist.c:89:7: /usr/include/x86_64-linux-gnu/bits/string_fortified.h:95:10: warning: ‘strncpy’ output may be truncated copying 30 bytes from a string of length 255 [-Wstringop-truncation] 95 | return __builtin___strncpy_chk (__dest, __src, __len, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 96 | __glibc_objsize (__dest)); | ~~~~~~~~~~~~~~~~~~~~~~~~~ /usr/include/x86_64-linux-gnu/bits/string_fortified.h:95:10: warning: ‘strncpy’ output may be truncated copying 30 bytes from a string of length 255 [-Wstringop-truncation] In function ‘strncpy’, inlined from ‘ReadALine’ at prochist.c:58:3, inlined from ‘read_system_history’ at prochist.c:90:7: /usr/include/x86_64-linux-gnu/bits/string_fortified.h:95:10: warning: ‘strncpy’ output may be truncated copying 30 bytes from a string of length 255 [-Wstringop-truncation] 95 | return __builtin___strncpy_chk (__dest, __src, __len, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 96 | __glibc_objsize (__dest)); | ~~~~~~~~~~~~~~~~~~~~~~~~~ /usr/include/x86_64-linux-gnu/bits/string_fortified.h:95:10: warning: ‘strncpy’ output may be truncated copying 30 bytes from a string of length 255 [-Wstringop-truncation] gcc -c -DLOCALEDIR=\"/usr/share/locale\" -DHAVE_CONFIG_H -DLIBDIR=\"/etc\" -I. -I.. -I../intl -I../intl -Wdate-time -D_FORTIFY_SOURCE=2 -g -O2 -ffile-prefix-map=/<<PKGBUILDDIR>>=. -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -Wall reports.c reports.c: In function ‘print_the_system_summary’: reports.c:283:20: warning: type defaults to ‘int’ in declaration of ‘idx’ [-Wimplicit-int] 283 | register idx; | ^~~ reports.c: In function ‘time_to_string’: reports.c:53:32: warning: ‘%02d’ directive writing between 2 and 11 bytes into a region of size between 0 and 3 [-Wformat-overflow=] 53 | sprintf (str, "%4d:%02d:%02d.%02d", | ^~~~ In file included from /usr/include/stdio.h:866, from tua.h:80, from reports.c:23: /usr/include/x86_64-linux-gnu/bits/stdio2.h:38:10: note: ‘__sprintf_chk’ output between 14 and 32 bytes into a destination of size 14 38 | return __builtin___sprintf_chk (__s, __USE_FORTIFY_LEVEL - 1, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 39 | __glibc_objsize (__s), __fmt, | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 40 | __va_arg_pack ()); | ~~~~~~~~~~~~~~~~~ gcc -c -DLOCALEDIR=\"/usr/share/locale\" -DHAVE_CONFIG_H -DLIBDIR=\"/etc\" -I. -I.. -I../intl -I../intl -Wdate-time -D_FORTIFY_SOURCE=2 -g -O2 -ffile-prefix-map=/<<PKGBUILDDIR>>=. -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -Wall sysalias.c gcc -c -DLOCALEDIR=\"/usr/share/locale\" -DHAVE_CONFIG_H -DLIBDIR=\"/etc\" -I. -I.. -I../intl -I../intl -Wdate-time -D_FORTIFY_SOURCE=2 -g -O2 -ffile-prefix-map=/<<PKGBUILDDIR>>=. -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -Wall systree.c gcc -c -DLOCALEDIR=\"/usr/share/locale\" -DHAVE_CONFIG_H -DLIBDIR=\"/etc\" -I. -I.. -I../intl -I../intl -Wdate-time -D_FORTIFY_SOURCE=2 -g -O2 -ffile-prefix-map=/<<PKGBUILDDIR>>=. -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -Wall tmparse.c gcc -c -DLOCALEDIR=\"/usr/share/locale\" -DHAVE_CONFIG_H -DLIBDIR=\"/etc\" -I. -I.. -I../intl -I../intl -Wdate-time -D_FORTIFY_SOURCE=2 -g -O2 -ffile-prefix-map=/<<PKGBUILDDIR>>=. -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -Wall trees.c gcc -c -DLOCALEDIR=\"/usr/share/locale\" -DHAVE_CONFIG_H -DLIBDIR=\"/etc\" -I. -I.. -I../intl -I../intl -Wdate-time -D_FORTIFY_SOURCE=2 -g -O2 -ffile-prefix-map=/<<PKGBUILDDIR>>=. -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -Wall tua.c gcc -c -DLOCALEDIR=\"/usr/share/locale\" -DHAVE_CONFIG_H -DLIBDIR=\"/etc\" -I. -I.. -I../intl -I../intl -Wdate-time -D_FORTIFY_SOURCE=2 -g -O2 -ffile-prefix-map=/<<PKGBUILDDIR>>=. -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -Wall useralias.c gcc -c -DLOCALEDIR=\"/usr/share/locale\" -DHAVE_CONFIG_H -DLIBDIR=\"/etc\" -I. -I.. -I../intl -I../intl -Wdate-time -D_FORTIFY_SOURCE=2 -g -O2 -ffile-prefix-map=/<<PKGBUILDDIR>>=. -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -Wall usertree.c gcc -flto=auto -ffat-lto-objects -Wl,-z,relro -o tua globalias.o wildmat.o commtree.o compat.o daytree.o debug.o julian.o pcdl.o pcdl_gram.o phonesw.o portalias.o porttree.o process.o prochist.o reports.o sysalias.o systree.o tmparse.o trees.o tua.o useralias.o usertree.o libtua.a /usr/bin/ld: /tmp/cctBepsp.ltrans0.ltrans.o: in function `read_log_log': /<<PKGBUILDDIR>>/src/taylor/log.c:77: undefined reference to `strbegcmp' /usr/bin/ld: /tmp/cctBepsp.ltrans0.ltrans.o:/<<PKGBUILDDIR>>/src/taylor/log.c:85: undefined reference to `strbegcmp' /usr/bin/ld: /tmp/cctBepsp.ltrans0.ltrans.o: in function `read_log_log': /<<PKGBUILDDIR>>/src/taylor/proclog.c:170: undefined reference to `strbegcmp' /usr/bin/ld: /tmp/cctBepsp.ltrans0.ltrans.o:/<<PKGBUILDDIR>>/src/taylor/proclog.c:189: undefined reference to `strbegcmp' /usr/bin/ld: /tmp/cctBepsp.ltrans0.ltrans.o:/<<PKGBUILDDIR>>/src/taylor/log.c:95: undefined reference to `strbegcmp' /usr/bin/ld: /tmp/cctBepsp.ltrans0.ltrans.o:/<<PKGBUILDDIR>>/src/taylor/proclog.c:152: more undefined references to `strbegcmp' follow collect2: error: ld returned 1 exit status make[2]: *** [Makefile:105: tua] Error 1 make[2]: Leaving directory '/<<PKGBUILDDIR>>/src' make[1]: *** [Makefile:45: all] Error 1 make[1]: Leaving directory '/<<PKGBUILDDIR>>' make: *** [debian/rules:15: build] Error 2 dpkg-buildpackage: error: debian/rules build subprocess returned exit status 2