Bug#808655: frown: FTBFS: No instance for (Applicative Set)

[Chris West (Faux)]

Source: frown
Version: 0.6.1-14
Severity: serious
Justification: fails to build from source
Tags: sid 
User: reproducible-builds at lists.alioth.debian.org
Usertags: ftbfs
X-Debbugs-CC: reproducible-builds at lists.alioth.debian.org

Dear Maintainer,

The package fails to build:

[ 5 of 26] Compiling Prettier         ( Lib/Prettier.lhs, Lib/Prettier.o )
[ 6 of 26] Compiling Atom             ( Atom.lhs, Atom.o )
[ 7 of 26] Compiling OrdUniqListSet   ( Lib/OrdUniqListSet.lhs, Lib/OrdUniqListSet.o )

Lib/OrdUniqListSet.lhs:115:12:
    No instance for (Applicative Set)
      arising from the superclasses of an instance declaration
    In the instance declaration for ‘Monad Set’
Makefile:57: recipe for target 'frown' failed
make[1]: *** [frown] Error 1
make[1]: Leaving directory '/frown-0.6.1'
/usr/share/cdbs/1/class/makefile.mk:47: recipe for target 'debian/stamp-makefile-build' failed
make: *** [debian/stamp-makefile-build] Error 2
dpkg-buildpackage: error: debian/rules build gave error exit status 2

Full build log:
https://reproducible.debian.net/rb-pkg/unstable/amd64/frown.html

-- System Information:
Debian Release: stretch/sid
APT prefers unstable
APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)