[Debian-astro-maintainers] Bug#1018157: wsclean: FTBFS on riscv64 (undefined reference to `__atomic_exchange_1')

[Eric Long]

Source: wsclean
Version: 3.1-1
Severity: important
Tags: ftbfs patch
Justification: fails to build from source (but built successfully in the past)
X-Debbugs-Cc: i at hack3r.moe

Dear maintainer,

wsclean failed to build on riscv64:

```
[100%] Built target wsclean-shared
/usr/bin/ld: libwsclean.a(msgridderbase.cpp.o): in function `MSGridderBase::getAvailableMemory(double, double)':
./obj-riscv64-linux-gnu/./gridding/msgridderbase.cpp:300: undefined reference to `__atomic_exchange_1'
collect2: error: ld returned 1 exit status
make[3]: *** [CMakeFiles/wsclean.dir/build.make:154: wsclean] Error 1
make[3]: Leaving directory '/<<PKGBUILDDIR>>/obj-riscv64-linux-gnu'
make[2]: *** [CMakeFiles/Makefile2:286: CMakeFiles/wsclean.dir/all] Error 2
make[2]: Leaving directory '/<<PKGBUILDDIR>>/obj-riscv64-linux-gnu'
make[1]: *** [Makefile:139: all] Error 2
make[1]: Leaving directory '/<<PKGBUILDDIR>>/obj-riscv64-linux-gnu'
dh_auto_build: error: cd obj-riscv64-linux-gnu && make -j4 "INSTALL=install --strip-program=true" VERBOSE=1 returned exit code 2
make: *** [debian/rules:10: binary-arch] Error 25
dpkg-buildpackage: error: debian/rules binary-arch subprocess returned exit status 2
```

Full buildd log: https://buildd.debian.org/status/fetch.php?pkg=wsclean&arch=riscv64&ver=3.1-1&stamp=1653411048&raw=0

Attached is a patch that links libatomic on riscv64 and fixes FTBFS, tested on
my QEMU riscv64 machine. Please let me know if I missed something.

Cheers,
Eric

-- System Information:
Debian Release: bookworm/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 5.18.0-4-amd64 (SMP w/8 CPU threads; PREEMPT)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
-------------- next part --------------
Description: Link libatomic against wsclean-lib on riscv64 and fix FTBFS
Author: Eric Long <i at hack3r.moe>
Last-Update: 2022-08-26
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -381,6 +381,9 @@
 
 add_library(wsclean-lib STATIC ${WSCLEANFILES})
 target_link_libraries(wsclean-lib PRIVATE pybind11::embed ${ALL_LIBRARIES})
+if(${CMAKE_SYSTEM_PROCESSOR} STREQUAL "riscv64")
+    target_link_libraries(wsclean-lib PRIVATE -latomic)
+endif()
 set_target_properties(wsclean-lib PROPERTIES OUTPUT_NAME wsclean)
 set_target_properties(wsclean-lib PROPERTIES SOVERSION ${WSCLEAN_VERSION_SO})