Silence gen_contents_index for the common case.
The line: echo $HADDOCK_ARGS
Was introduced in: https://github.com/ghc/ghc/commit/2ad79aaa1b87164a0191e8f980f57a9fa0b80e0a
In archlinux (and other distros), gen_contents_index is run after installing a package using the distro's package manager to update the index file containing the list of libraries.
As a result of the commit, the output when installing a package can get very verbose.
Since the original intention of this change was to make it easier to debug crashes, I propose that there be a flag introduced into this script --verbose or --debug which would print out $HADDOCK_ARGS when specified so that the common case wouldn't include all the extra unneeded output.
I am willing to write a patch for this, if this idea is accepted.