Compilation time for the mime-string package blew up from 8.4 to 8.6
Summary
The mime-string
Hackage package takes ~7 minutes to compile on my machine with a GHC >= 8.6. With GHC-8.4.4 it was building in < 20s including some dependencies.
Most of the time seems to be spent on the Codec.MIME.String.Headers
and especially the Codec.MIME.String.Date
module.
With GHC-8.10-HEAD, cabal
seems to default to building to .dyn_o
files too, which seems to increase compile time so much that building Codec.MIME.String.Headers
alone takes > 20 minutes.
The issue was originally reported in this discourse.haskell.org thread.
Steps to reproduce
- Download
T17516A.hs
andT17516B.hs
ghc -O T17516A.hs T17516B.hs
Expected behavior
The build should take no longer than about 30s.
Environment
- GHC version used: 8.6.5
- Operating System: Ubuntu 16.04
- System Architecture: x86_64