OpenSSL 4.0 is in experimental. This package fails to build against it:
|-- Found OpenSSL: /usr/lib/x86_64-linux-gnu/libcrypto.so (found suitable version "4.0.0", minimum required is "1.1.1")
|-- Found PCSC: @foreign_pkgcfg::libpcsclite
|CMake Error at cmake/Libraries.cmake:188 (message):
|  Your OpenSSL library looks incompatible: 1
|
…
|  /usr/bin/x86_64-linux-gnu-ld.bfd: warning: libcrypto.so.3, needed by
|  /usr/lib/x86_64-linux-gnu/libldap.so.2, may conflict with libcrypto.so.4
|
|  /usr/bin/c++ -g -O2
|  -ffile-prefix-map=/build/reproducible-path/ausweisapp2-2.5.1=.
|  -fstack-protector-strong -fstack-clash-protection -Wformat
|  -Werror=format-security -fcf-protection -Wdate-time -D_FORTIFY_SOURCE=2
|  -Wl,-z,relro CMakeFiles/cmTC_41e88.dir/openssl.cpp.o -o cmTC_41e88
|  /usr/lib/x86_64-linux-gnu/libQt6Network.so.6.10.2
|  /usr/lib/x86_64-linux-gnu/libcrypto.so /usr/lib/x86_64-linux-gnu/libssl.so
|  /usr/lib/x86_64-linux-gnu/libQt6Core.so.6.10.2
|  /usr/lib/x86_64-linux-gnu/libcrypto.so

Full buildlog
https://breakpoint.cc/openssl-rebuild/logs-4/attempted/ausweisapp2_2.5.1-1_amd64-2026-04-19T13:27:15Z

Sebastian

Dear Maintainer,

The attached patch along with the follofing change in the rules file fixes the build error.

+override_dh_auto_configure:
+	dh_auto_configure -- -DUSE_LEGACY_OPENSSL_API=ON
+

Regards
Ravi

Hello Ravi,

Thanks for the patch!

There is a new upstream version 2.6.0 coming soon which will take
care of this flag automatically. But let me upload 2.5.5 in the
mean time.

Adrian

We believe that the bug you reported is fixed in the latest version of
ausweisapp2, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 1137473@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> (supplier of updated ausweisapp2 package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)
Format: 1.8
Date: Wed, 07 Oct 2026 07:36:13 +0200
Source: ausweisapp2
Architecture: source
Version: 2.6.0-1
Distribution: unstable
Urgency: medium
Maintainer: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Changed-By: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Closes: 1137473
Changes:
 ausweisapp2 (2.6.0-1) unstable; urgency=medium
 .
   * New upstream release (Closes: #1137473)
Checksums-Sha1:
 c0d002b05c0bdada5a150ade5d626b52e61d21ef 2149 ausweisapp2_2.6.0-1.dsc
 1e017d3644b4be5d087fcac663d21876df0e68bf 6061045 ausweisapp2_2.6.0.orig.tar.gz
 126736191e1b3f4140a63ed63d996b870706a1c5 8708 ausweisapp2_2.6.0-1.debian.tar.xz
 9ed8b22f0ed3a2c028454502fa83298ab5a62e8b 16246 ausweisapp2_2.6.0-1_amd64.buildinfo
Checksums-Sha256:
 658778d6480e7caf4fe21182e9be76e523579d0bbc4470b7ffd355cee2505ace 2149 ausweisapp2_2.6.0-1.dsc
 bc127ded9abbae38882b8d85edabc9ab7277c9265bc2744640f1eae6c88677bc 6061045 ausweisapp2_2.6.0.orig.tar.gz
 ff3fb3ff3cfcf063f8577f85b106fb37b6e03959fb26bda5a16b8e2bb51ac427 8708 ausweisapp2_2.6.0-1.debian.tar.xz
 6ade9bb48e654c50cb77f9a07dcc3e2aae1c387061293ba3322aa0521ea97675 16246 ausweisapp2_2.6.0-1_amd64.buildinfo
Files:
 7da42a72aba3aed58399c734e23a4bfb 2149 utils optional ausweisapp2_2.6.0-1.dsc
 3aa4d7928342e99e42c27b34b1ee02d5 6061045 utils optional ausweisapp2_2.6.0.orig.tar.gz
 e7a5453a518dcf7916273320ec382cfd 8708 utils optional ausweisapp2_2.6.0-1.debian.tar.xz
 1dfa76482ce96be1c748a2e718cb5dda 16246 utils optional ausweisapp2_2.6.0-1_amd64.buildinfo
-----BEGIN PGP SIGNATURE-----
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=IYHo
-----END PGP SIGNATURE-----