#1128682 libsmb2: FTBFS with glibc 2.43 due to ISO C23 const return types

Package:
src:libsmb2
Source:
src:libsmb2
Submitter:
Aurelien Jarno
Date:
2026-02-22 16:03:02 UTC
Severity:
normal
Tags:
#1128682#5
Date:
2026-02-22 12:32:31 UTC
From:
To:
Dear maintainer(s),

libsmb2 fails to build from source with glibc 2.43, currently in
experimental. From the build log:

| /bin/bash ../libtool  --tag=CC   --mode=compile gcc -DHAVE_CONFIG_H -I. -I..  -I/build/reproducible-path/libsmb2-6.2+dfsg/include -I/build/reproducible-path/libsmb2-6.2+dfsg/include/smb2 "-D_U_=__attribute__((unused))" -Wdate-time -D_FORTIFY_SOURCE=2 -Wall -Wshadow -Wno-write-strings -Wstrict-prototypes -Wpointer-arith -Wcast-align -Wno-strict-aliasing -Werror -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/libsmb2-6.2+dfsg=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -mbranch-protection=standard -D_FILE_OFFSET_BITS=64 -c -o libsmb2_la-init.lo `test -f 'init.c' || echo './'`init.c

...

| libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I.. -I/build/reproducible-path/libsmb2-6.2+dfsg/include -I/build/reproducible-path/libsmb2-6.2+dfsg/include/smb2 "-D_U_=__attribute__((unused))" -Wdate-time -D_FORTIFY_SOURCE=2 -Wall -Wshadow -Wno-write-strings -Wstrict-prototypes -Wpointer-arith -Wcast-align -Wno-strict-aliasing -Werror -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/libsmb2-6.2+dfsg=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -mbranch-protection=standard -D_FILE_OFFSET_BITS=64 -c init.c  -fPIC -DPIC -o .libs/libsmb2_la-init.o

...

| init.c: In function 'smb2_parse_args':
| init.c:92:22: error: assignment discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
|    92 |                 next = strchr(args, '&');
|       |                      ^
| init.c:97:23: error: assignment discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
|    97 |                 value = strchr(args, '=');
|       |                       ^

| make[3]: *** [Makefile:721: libsmb2_la-init.lo] Error 1
| make[3]: *** Waiting for unfinished jobs....
| make[3]: Leaving directory '/build/reproducible-path/libsmb2-6.2+dfsg/lib'
| make[2]: *** [Makefile:464: all-recursive] Error 1
| make[2]: Leaving directory '/build/reproducible-path/libsmb2-6.2+dfsg'
| make[1]: *** [Makefile:373: all] Error 2
| make[1]: Leaving directory '/build/reproducible-path/libsmb2-6.2+dfsg'
| dh_auto_build: error: make -j128 returned exit code 2
| make: *** [debian/rules:6: binary] Error 25
| 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/libsmb2_arm64.build
[2] https://sourceware.org/git/?p=glibc.git;a=blob;f=NEWS;h=e271fb2e4d76903c77a302aaec1ca22ce31027d0;hb=f762ccf84f122d1354f103a151cba8bde797d521#l19