Bug#867194: haskell-terminal-progress-bar FTBFS: Haddock failed (no modules?), refusing to create empty documentation package

[Adrian Bunk]

Source: haskell-terminal-progress-bar
Version: 0.0.1.4-8
Severity: serious
Tags: buster sid

Some recent change in unstable makes haskell-terminal-progress-bar FTBFS:

https://tests.reproducible-builds.org/debian/history/haskell-terminal-progress-bar.html
https://tests.reproducible-builds.org/debian/rb-pkg/unstable/amd64/haskell-terminal-progress-bar.html

...
/usr/bin/haddock '@dist-ghc/doc/html/terminal-progress-bar/haddock-response16816927771714636915.txt' '--mathjax=file:///usr/share/javascript/mathjax/MathJax.js'
Haddock coverage:
  86% ( 12 / 14) in 'System.ProgressBar'
  Missing documentation for:
    Module header
    ProgressRef (src/System/ProgressBar.hs:162)
Warning: System.ProgressBar: could not find link destinations for:
    haddock: internal error: <stdout>: commitBuffer: invalid argument (invalid character)
Haddock failed (no modules?), refusing to create empty documentation package.
/usr/share/cdbs/1/class/hlibrary.mk:173: recipe for target 'build-haddock-stamp' failed
make: *** [build-haddock-stamp] Error 1