https://buildd.debian.org/status/package.php?p=haskell-regex-compat-tdfa&suite=sid

...
Text/Regex.hs:142:22: error:
    Bang pattern in expression context: !0
    Did you mean to add a space after the '!'?
    |
142 |   let matches = map (!0) (matchAll delim strIn)
    |                      ^^
 at /usr/share/perl5/Debian/Debhelper/Buildsystem/Haskell/Recipes.pm line 107.
	Debian::Debhelper::Buildsystem::Haskell::Recipes::run_quiet("debian/hlibrary.setup", "haddock", "--builddir=dist-ghc", "--with-haddock=/usr/bin/haddock", "--with-ghc=ghc", "--verbose=2", "--html", "--hoogle", ...) called at /usr/share/perl5/Debian/Debhelper/Buildsystem/Haskell/Recipes.pm line 131
	Debian::Debhelper::Buildsystem::Haskell::Recipes::run("debian/hlibrary.setup", "haddock", "--builddir=dist-ghc", "--with-haddock=/usr/bin/haddock", "--with-ghc=ghc", "--verbose=2", "--html", "--hoogle", ...) called at /usr/share/perl5/Debian/Debhelper/Buildsystem/Haskell/Recipes.pm line 707
	Debian::Debhelper::Buildsystem::Haskell::Recipes::haddock_recipe() called at -e line 1
make: *** [/usr/share/cdbs/1/class/hlibrary.mk:153: build-ghc-stamp] Error 25

Dear submitter,

as the package haskell-regex-compat-tdfa has just been removed from the Debian archive
unstable we hereby close the associated bug reports.  We are sorry
that we couldn't deal with your issue properly.

For details on the removal, please see https://bugs.debian.org/1029341

The version of this package that was in Debian prior to this removal
can still be found using https://snapshot.debian.org/.

Please note that the changes have been done on the master archive and
will not propagate to any mirrors until the next dinstall run at the
earliest.

This message was generated automatically; if you believe that there is
a problem with it please contact the archive administrators by mailing
ftpmaster@ftp-master.debian.org.

Debian distribution maintenance software
pp.
Scott Kitterman (the ftpmaster behind the curtain)