[Debian-iot-maintainers] Bug#1126819: ulfius: FTBFS with glibc 2.43 due to ISO C23 const return types

[Aurelien Jarno]

Source: ulfius
Version: 2.7.15-2.2
Severity: important
Tags: ftbfs upstream
Justification: fails to build from source
User: debian-glibc at lists.debian.org
Usertags: glibc-2.43

Dear maintainer,

ulfius fails to build from source with glibc 2.43, currently in
experimental. From the build log:

| [ 91%] Building C object CMakeFiles/core.dir/example_callbacks/static_compressed_inmemory_website/static_compressed_inmemory_website_callback.c.o
| /usr/bin/cc -D_GNU_SOURCE -I/build/reproducible-path/ulfius-2.7.15/include -I/build/reproducible-path/ulfius-2.7.15/test -I/build/reproducible-path/ulfius-2.7.15/example_callbacks/http_compression -I/build/reproducible-path/ulfius-2.7.15/example_callbacks/static_compressed_inmemory_website -I/build/reproducible-path/ulfius-2.7.15/build -isystem /usr/include/subunit -Wall -Werror -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/ulfius-2.7.15=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -fcf-protection -Wdate-time -D_FORTIFY_SOURCE=2 -std=gnu99 -MD -MT CMakeFiles/core.dir/example_callbacks/static_compressed_inmemory_website/static_compressed_inmemory_website_callback.c.o -MF CMakeFiles/core.dir/example_callbacks/static_compressed_inmemory_website/static_compressed_inmemory_website_callback.c.o.d -o CMakeFiles/core.dir/example_callbacks/static_compressed_inmemory_website/static_compressed_inmemory_website_callback.c.o -c /build/reproducible-path/ulfius-2.7.15/example_callbacks/static_compressed_inmemory_website/static_compressed_inmemory_website_callback.c
| /build/reproducible-path/ulfius-2.7.15/example_callbacks/static_compressed_inmemory_website/static_compressed_inmemory_website_callback.c: In function ‘get_filename_ext’:
| /build/reproducible-path/ulfius-2.7.15/example_callbacks/static_compressed_inmemory_website/static_compressed_inmemory_website_callback.c:131:25: error: assignment of read-only location ‘*(const char *)strchr(dot, 63)’
|   131 |       *strchr(dot, '?') = '\0';
|       |                         ^
| gmake[6]: *** [CMakeFiles/core.dir/build.make:110: CMakeFiles/core.dir/example_callbacks/static_compressed_inmemory_website/static_compressed_inmemory_website_callback.c.o] Error 1
| gmake[6]: Leaving directory '/build/reproducible-path/ulfius-2.7.15/build'
| gmake[5]: *** [CMakeFiles/Makefile2:164: CMakeFiles/core.dir/all] Error 2
| gmake[5]: Leaving directory '/build/reproducible-path/ulfius-2.7.15/build'
| gmake[4]: *** [CMakeFiles/Makefile2:171: CMakeFiles/core.dir/rule] Error 2
| gmake[4]: Leaving directory '/build/reproducible-path/ulfius-2.7.15/build'
| gmake[3]: *** [Makefile:228: core] Error 2
| gmake[3]: Leaving directory '/build/reproducible-path/ulfius-2.7.15/build'
| Problem running command: /usr/bin/gmake core u_map framework example_callbacks websocket
| Problem executing pre-test command(s).
| Errors while running CTest
| make[2]: *** [Makefile:94: test] Error 8
| make[2]: Leaving directory '/build/reproducible-path/ulfius-2.7.15/build'
| make[1]: *** [debian/rules:28: override_dh_auto_test] Error 2
| make[1]: Leaving directory '/build/reproducible-path/ulfius-2.7.15'
| make: *** [debian/rules:11: binary] Error 2
| dpkg-buildpackage: error: debian/rules binary subprocess failed with exit status 2

The full build log is attached to this bug report.

The issue is due to ISO C23 declaration of strchr, which now returns a
pointer to a const-qualified type when the input argument is a pointer
to a const-qualified type [1].

Regards
Aurelien

[1] https://sourceware.org/git/?p=glibc.git;a=blob;f=NEWS;h=e271fb2e4d76903c77a302aaec1ca22ce31027d0;hb=f762ccf84f122d1354f103a151cba8bde797d521#l19
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