#1128748 sane-backends: FTBFS with glibc 2.43 due to ISO C23 const return types

Package:
src:sane-backends
Source:
src:sane-backends
Submitter:
Aurelien Jarno
Date:
2026-08-10 12:53:21 UTC
Severity:
normal
Tags:
#1128748#5
Date:
2026-02-22 16:17:59 UTC
From:
To:
Dear maintainer(s),

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

| /bin/bash ../libtool --silent  --tag=CC   --mode=compile gcc -DHAVE_CONFIG_H -I. -I../include/sane  -D_REENTRANT -DPATH_SANE_CONFIG_DIR=/etc/sane.d 	  -DPATH_SANE_DATA_DIR=/usr/share 	  -DPATH_SANE_LOCK_DIR=/var/lock 	  -DV_MAJOR=1 -DV_MINOR=2 -I. -I. -I../include -I../include -I/usr/include/libusb-1.0 -DLIBDIR="\"/usr/lib/aarch64-linux-gnu/sane\"" -DDEB_DLL_LIBDIR="\"/usr/lib/aarch64-linux-gnu/sane:/usr/lib/sane:/usr/lib64/sane\"" -I/usr/include/gphoto2 -DBACKEND_NAME=gphoto2 -Wdate-time -D_FORTIFY_SOURCE=2 -Wall -Wextra -pedantic -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/sane-backends-1.4.0=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -mbranch-protection=standard -c -o libgphoto2_i_la-gphoto2.lo `test -f 'gphoto2.c' || echo './'`gphoto2.c
| gphoto2.c: In function 'get_info':
| gphoto2.c:589:60: error: assignment of read-only location '*(const char *)strchr((const char *)*(folder_list + (sizetype)((long unsigned int)n * 8)), 32)'
|   589 |               *strchr ((const char *) folder_list[n], ' ') = '\0';
|       |                                                            ^
| make[5]: *** [Makefile:5842: libgphoto2_i_la-gphoto2.lo] Error 1
| make[5]: Leaving directory '/build/reproducible-path/sane-backends-1.4.0/backend'
| make[4]: *** [Makefile:4308: all] Error 2
| make[4]: Leaving directory '/build/reproducible-path/sane-backends-1.4.0/backend'
| make[3]: *** [Makefile:613: all-recursive] Error 1
| make[3]: Leaving directory '/build/reproducible-path/sane-backends-1.4.0'
| make[2]: *** [Makefile:503: all] Error 2
| make[2]: Leaving directory '/build/reproducible-path/sane-backends-1.4.0'
| make[1]: *** [debian/rules:64: override_dh_auto_build-indep] Error 2
| make[1]: Leaving directory '/build/reproducible-path/sane-backends-1.4.0'
| make: *** [debian/rules:23: binary] Error 2
| dpkg-buildpackage: error: debian/rules binary subprocess failed with exit status 2

The full build log is available here [1].

The issue is due to ISO C23 declaration of bsearch, memchr, strchr,
strpbrk, strrchr, strstr, wcschr, wcspbrk, wcsrchr, wcsstr and wmemchr,
which now returns a pointer to a const-qualified type when the input
argument is a pointer to a const-qualified type [2].

I would like to thanks Emanuele Rocca for doing the archive rebuild on
a fast arm64 server.

Regards
Aurelien

[1] https://people.debian.org/~ema/glibc-2.43-rebuilds/output-1/sane-backends_arm64.build
[2] https://sourceware.org/git/?p=glibc.git;a=blob;f=NEWS;h=e271fb2e4d76903c77a302aaec1ca22ce31027d0;hb=f762ccf84f122d1354f103a151cba8bde797d521#l19

#1128748#10
Date:
2026-02-23 10:40:03 UTC
From:
To:
forwarded 1128748 https://gitlab.com/sane-project/backends/-/issues/847
thanks


Hi,

thank you for your bug report.


CU
Jörg

#1128748#21
Date:
2026-08-10 12:44:53 UTC
From:
To:
control: severity 1127629 serious
control: severity 1128547 serious
control: severity 1128734 serious
control: severity 1128740 serious
control: severity 1128528 serious
control: severity 1128532 serious
control: severity 1128534 serious
control: severity 1128541 serious
control: severity 1128544 serious
control: severity 1128545 serious
control: severity 1128548 serious
control: severity 1128549 serious
control: severity 1128551 serious
control: severity 1128615 serious
control: severity 1128678 serious
control: severity 1128680 serious
control: severity 1128681 serious
control: severity 1128697 serious
control: severity 1128736 serious
control: severity 1128737 serious
control: severity 1128738 serious
control: severity 1128741 serious
control: severity 1128742 serious
control: severity 1128743 serious
control: severity 1128750 serious
control: severity 1128757 serious
control: severity 1128761 serious
control: severity 1128763 serious
control: severity 1128764 serious
control: severity 1128875 serious
control: severity 1128952 serious
control: severity 1128542 serious
control: severity 1128679 serious
control: severity 1128682 serious
control: severity 1128744 serious
control: severity 1128748 serious
control: severity 1128867 serious

Hi,

With the upload of glibc 2.43 to unstable, the packages now FTBFS in
unstable, hence upgrading the severity to serious.

Note that as a quick workaround, it is possible to roll back to C/C++17
standard using -std=c17, -std=gnu17, std=c++17 or std=gnu++17. This was
the default up to GCC 14, and GCC 15 changed it to C/C23.

Regards
Aurelien