Bug#981718: haskell-basement: ftbfs probably in document generation

[Ritesh Raj Sarraf]

Source: haskell-basement
Version: 0.0.11-1
Severity: serious
Tags: ftbfs
Justification: fails to build from source (but built successfully in the past)

The package fails to build in Bullseye. The same is also reflected in
the Reproducible build status

Incomplete build failure snippet

```
Warning: 'unsafeIndexer' is out of scope.
    If you qualify the identifier, haddock can try to link it anyway.
   0% (  0 / 27) in 'Basement.Sized.UVect'
  Missing documentation for:
    Module header
    UVect (Basement/Sized/UVect.hs:47)
    MUVect (Basement/Sized/UVect.hs:48)
    unUVect (Basement/Sized/UVect.hs:47)
    toUVect (Basement/Sized/UVect.hs:50)
    empty (Basement/Sized/UVect.hs:57)
    singleton (Basement/Sized/UVect.hs:60)
    replicate (Basement/Sized/UVect.hs:68)
    thaw (Basement/Sized/UVect.hs:71)
    freeze (Basement/Sized/UVect.hs:74)
    index (Basement/Sized/UVect.hs:86)
    map (Basement/Sized/UVect.hs:89)
    foldl' (Basement/Sized/UVect.hs:92)
    foldr (Basement/Sized/UVect.hs:95)
    cons (Basement/Sized/UVect.hs:98)
    snoc (Basement/Sized/UVect.hs:101)
    elem (Basement/Sized/UVect.hs:134)
    sub (Basement/Sized/UVect.hs:104)
    uncons (Basement/Sized/UVect.hs:117)
    unsnoc (Basement/Sized/UVect.hs:122)
    splitAt (Basement/Sized/UVect.hs:129)
    all (Basement/Sized/UVect.hs:137)
    any (Basement/Sized/UVect.hs:140)
    find (Basement/Sized/UVect.hs:143)
    reverse (Basement/Sized/UVect.hs:146)
    sortBy (Basement/Sized/UVect.hs:149)
    intersperse (Basement/Sized/UVect.hs:152)
Warning: 'A' is out of scope.
    If you qualify the identifier, haddock can try to link it anyway.
Warning: 'haddock: internal error: <stdout>: commitBuffer: invalid argument (invalid character)
Haddock failed (no modules?), refusing to create empty documentation package.
make: *** [/usr/share/cdbs/1/class/hlibrary.mk:173: build-haddock-stamp] Error 1
dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2
I: copying local configuration
E: Failed autobuilding of package
I: unmounting dev/ptmx filesystem
I: unmounting dev/pts filesystem
I: unmounting dev/shm filesystem
I: unmounting proc filesystem
```

Full build log:
https://tests.reproducible-builds.org/debian/rb-pkg/bullseye/amd64/haskell-basement.html


-- System Information:
Debian Release: bullseye/sid
  APT prefers unstable
  APT policy: (990, 'unstable'), (990, 'testing'), (500, 'stable-updates'), (500, 'stable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.10.0-3-amd64 (SMP w/8 CPU threads)
Kernel taint flags: TAINT_USER
Locale: LANG=en_IN.UTF-8, LC_CTYPE=en_IN.UTF-8 (charmap=UTF-8), LANGUAGE=en_US
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled