Opened 15 months ago

Closed 7 months ago

#14525 closed bug (fixed)

Backpack doesn't work with CPP

Reported by: ezyang Owned by:
Priority: normal Milestone:
Component: Compiler Version: 8.2.2
Keywords: backpack Cc:
Operating System: Unknown/Multiple Architecture: Unknown/Multiple
Type of failure: None/Unknown Test Case:
Blocked By: Blocking:
Related Tickets: Differential Rev(s): Phab:D4234
Wiki Page:


Steps to repro:

  1. Create a package with a signature and a module which imports it
  2. Add {-# LANGUAGE CPP #-} to the module

Expected result: it works

Actual result:

<command line>: unknown package: hole

Change History (3)

comment:1 Changed 15 months ago by ezyang

Differential Rev(s): Phab:D4234
Status: newpatch

comment:2 Changed 15 months ago by Edward Z. Yang <ezyang@…>

In e1fb283/ghc:

Handle CPP properly in Backpack

Previously, we attempted to lookup 'hole' packages for
include directories; this obviously is not going to work.

Signed-off-by: Edward Z. Yang <>

Test Plan: validate

Reviewers: ekmett, bgamari

Subscribers: rwbarton, thomie

GHC Trac Issues: #14525

Differential Revision:

comment:3 Changed 7 months ago by ezyang

Resolution: fixed
Status: patchclosed
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