#11256: ghc --make reports bad import errors too eagerly -------------------------------------+------------------------------------- Reporter: ezyang | Owner: ezyang Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 7.11 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Consider this A.hs file, with a valid header (no B.hs file) and a syntax error: {{{ module A where import B = as7df89a235r a23jk @A#$(&#$A }}} We get different behavior when one-shot compiling and make compiling: {{{ ezyang@sabre:~$ ghc -c A.hs A.hs:4:1: parse error on input `=' ezyang@sabre:~$ ghc --make A.hs A.hs:2:8: Could not find module `B' Use -v to see a list of the files searched for. }}} I feel like the `--make` error is wrong, and we shouldn't actually complain that an import is missing until we build it. But it cuts both ways; if you have a big module graph and you try to `--make`, currently `--make` will report instantaneously if any import is wrong; if we changed this behavior, `--make` would chug along until it actually tried to compile the offending file. It's easy to fix and I can easily submit a patch for it, if people think we should defer the error. Doing this will also let me remove a grievous hack from my fix to #11244. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11256 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler