adding lib6-dev to stage-package directly or indirectly breaks build in snapcraft (only)

[Björn Michaelsen]

See attached snapcraft file to reproduce. The logfile shows the result: A very nasty non-obvious breaker of gcc stdlibs internals that show no hint at all towards at libatk1.0-dev being the culprit here. Removing it and this builds fine.

NOTE this is a just minimal reproduction scenario: In a usual upstream build, libwpd would be build along with the full build -- where other parts of LibreOffice need libatk. That fails in the same way.

So:
- Building libwpd outside of snapcraft works fine, even with libatk1.0-dev installed.
- libatk1.0-dev isnt intended used by the libwpd build. It shouldnt be affected by it in any way.
- the log suggests a very basic toolchain problem (nothing should _ever_ break mathcalls.h).
- possibly related to bug 1548232 (maybe same root cause).
- as bug 1548232, this might hint at more subtle toolchain breaks which dont show up at compile time, but only at runtime.

[Björn Michaelsen (bjoern-michaelsen)]

The problem is that libatk1.0-dev depends on libc6-dev, which causes this breakage. Thus currently adding any package that depends on libc6-dev directly or indirectly (libatk1.0-dev -> libglib2.0-dev -> zlib1g-dev -> libc6-dev) breaks this way. I bet that is a lot of packages that are currently unusable in snap.

[Björn Michaelsen (bjoern-michaelsen)]

adding "libc6-dev" to /usr/lib/python3/dist-packages/snapcraft/manifest.txt seems to fix this.

[Björn Michaelsen (bjoern-michaelsen)]

@Sergio: Can you have a look?

[Leo Arias (elopio)]

Confirmed. I get the same build error with latest snapcraft master.

[Kyle Fazzari (kyrofa)]

Sergio proposed the fix here: https://github.com/snapcore/snapcraft/pull/1951