git-annex 10.20230126-3 fails to build from source

[Benjamin Drung]

git-annex 10.20230126-3 fails to build from source:

```
[618 of 681] Compiling Assistant.WebApp.Types ( Assistant/WebApp/Types.hs, dist/build/git-annex/git-annex-tmp/Assistant/WebApp/Types.o, dist/build/git-annex/git-annex-tmp/Assistant/WebApp/Types.dyn_o )
/usr/bin/ld.gold: error: dist/build/git-annex/git-annex-tmp/Utility/Yesod.dyn_o: requires dynamic R_X86_64_PC32 reloc against 'UtilityziYesod_widgetFilezuw_closure' which may overflow at runtime; recompile with -fPIC
collect2: error: ld returned 1 exit status
`x86_64-linux-gnu-gcc' failed in phase `Linker'. (Exit code: 1)
```

Full amd64 build log: https://launchpadlibrarian.net/664477495/buildlog_ubuntu-mantic-amd64.git-annex_10.20230126-3_BUILDING.txt.gz

[Simon Chopin (schopin)]

I looked at this issue for quite a while. The package does *not* FTBFS in Debian. I tried passing various combinations of PIC and PIE flags to ghc, to no avail. Sadly, I wasn't able to even determine that the flags I gave made their way down to the linker invocation, since it's not possible for ghc to be loud in its invocation.

However, comparing the results of the Debian and Ubuntu compilation, the .o file contains in both cases the R_X86_64_PC32 relocation, which makes me think that it's a difference in linker behaviour. I wasn't able to find anything suspicious in our binutils delta with Debian.

I'm assigning this to GHC because it seems clearly a toolchain issue to me.

For whoever picks it up again, note that build parallelism is disabled at the top of d/rules. For your builds you might want to enable it again (simply use -j instead of -j1).