-Wunused-packages: not working with base-noprelude
Summary
Using -Wunused-packages
with base-noprelude
+ custom Prelude
results in incorrect warning that base-noprelude
is not needed for compilation.
Steps to reproduce
git clone git@github.com:AlistairB/unused-packages-repro.git
cd unused-packages-repro
cabal build
Warning is emitted by ghc:
<no location info>: warning: [-Wunused-packages]
The following packages were specified via -package or -package-id flags,
but were not needed for compilation:
- base-noprelude-4.14.1.0
Expected behavior
No warning should be emitted as base-noprelude
is required.
Removing base-noprelude
from build-depends
in the cabal file results in compilation failures due to missing modules as expected.
Environment
- GHC version used: 8.10.4
- Cabal version: 3.4
Optional:
- Operating System: Ubuntu 20.10
- System Architecture: x86
Edited by Alistair Burrowes