Hi, I believe the Perl rewrite of haskell-devscripts is nearly complete now. The package should probably be merged into dh-haskell eventually.
The Perl module should then become private, i.e. be shipped outside Perl's system path. It will discourage direct access of the sort that was documented in library.mk. For the time being, dh-haskell provides no bells and whistles. Any functionality you'd like to adopt—such as having certain substvars available—must be enabled manually. Fortunately, that is now easy due to the many small dh_* scripts. For the libraries from Hackage it means that any d/rules using the dh sequencer will include additional statements similar to the ones now found in hlibrary.mk, but instead in execute_after_dh_auto_install. Perhaps the build system should be augmented through the use of environmental variables. A setting of DH_HASKELL_MODULE=1 for example (or perhaps merely the presence of CABAL_PACKAGE) could enable the additional functionality needed in so many places. It should go right here in Debhelper's new Haskell build system. [1] Unfortunately, I recently switched to another operating system and may not be available to work on Debian's Haskell toolchain much longer—but I will still keep an eye out for new bugs for a little while longer. Kind regards, Felix Lechner [1] https://salsa.debian.org/haskell-team/dh-haskell/-/blob/history/lib/Debian/Debhelper/Buildsystem/haskell.pm#L203
