Re: Bug#1125774: ndpi: FTBFS on arm64: missing symbol

On 2026-01-17 Andreas Metzler <[email protected]> wrote:
[...]

> I am too stupid to understand this. config.log says:
> configure:22126: checking for gcry_cipher_checktag in -lgcrypt
> configure:22155: gcc -o conftest -W -Wall -Wno-unused-parameter -Wno-unused-function -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/home/ametzler/NDPI/ndpi-4.2=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -mbranch-protection=standard -I/usr/include/json-c  -Wdate-time -D_FORTIFY_SOURCE=2 -Wl,-z,relro -Wl,-z,now -mbranch-protection=standard conftest.c -lgcrypt  -ljson-c  -ljson-c  >&5
> /usr/lib/gcc/aarch64-linux-gnu/15/../../../aarch64-linux-gnu/libgcrypt.so: warning: GCS is required by -z gcs, but this shared library lacks the necessary property note. The dynamic loader might not enable GCS or refuse to load the program unless all the shared library dependencies have the GCS marking.
> configure:22155: $? = 0
> configure: failed program was:
> [...]
> configure:22167: result: no

> However, taking the snippped "failed program" and running the quoted
> "gcc -o conftest -W ..." on it yields the warning but exits
> successfully. (exit code 0).


A minimal configure.ac ...
AC_PREREQ(2.59)
AC_INIT([foonly], [2.0], [[email protected]])
AC_PROG_CC
AC_CHECK_LIB(gcrypt, gcry_cipher_checktag)
AC_CHECK_LIB(gpg-error, gpg_strerror_r)
AC_CONFIG_FILES([Makefile])
AC_OUTPUT

... indeed shows
checking for gcry_cipher_checktag in -lgcrypt... yes
checking for gpg_strerror_r in -lgpg-error... yes

with config.log saying
configure:3178: checking for gcry_cipher_checktag in -lgcrypt
configure:3207: gcc -o conftest -g -O2 -Werror=implicit-function-declaration -ff
ile-prefix-map=/home/ametzler/NDPI/blah=. -fstack-protector-strong -fstack-clash
-protection -Wformat -Werror=format-security -mbranch-protection=standard -Wdate
-time -D_FORTIFY_SOURCE=2 -Wl,-z,relro -Wl,-z,now -mbranch-protection=standard c
onftest.c -lgcrypt   >&5
/usr/lib/gcc/aarch64-linux-gnu/15/../../../aarch64-linux-gnu/libgcrypt.so: warni
ng: GCS is required by -z gcs, but this shared library lacks the necessary prope
rty note. The dynamic loader might not enable GCS or refuse to load the program
unless all the shared library dependencies have the GCS marking.
configure:3207: $? = 0
configure:3219: result: yes

cu Andreas