wiki:Building/KnownProblems

Version 4 (modified by simonmar, 9 years ago) (diff)

bring up to date and remove old/irrelevant stuff

Known pitfalls in building Glasgow Haskell

WARNINGS about pitfalls and known "problems":

  1. One difficulty that comes up from time to time is running out of space in TMPDIR. (It is impossible for the configuration stuff to compensate for the vagaries of different sysadmin approaches to temp space.)
    The quickest way around it is setenv TMPDIR /usr/tmp or even setenv TMPDIR . (or the equivalent incantation with your shell of choice).
    The best way around it is to say
    export TMPDIR=<dir>
    
    in your build.mk file. Then GHC and the other tools will use the appropriate directory in all cases.
  2. You may occasionally see a warning from the C compiler when compiling some Haskell code, eg. "warning: assignment from incompatible pointer type". These are usually harmless, but it's a good idea to report it on the mailing list so that we can fix it.
  3. Similarly, archiving warning messages like the following are not a problem:
    ar: filename GlaIOMonad__1_2s.o truncated to GlaIOMonad_
    ar: filename GlaIOMonad__2_2s.o truncated to GlaIOMonad_
    ...
    
  4. GHC's sources go through cpp before being compiled, and cpp varies a bit from one Unix to another. One particular gotcha is macro calls like this:
    SLIT("Hello, world")
    
    Some cpps treat the comma inside the string as separating two macro arguments, so you get
    :731: macro `SLIT' used with too many (2) args
    
    Alas, cpp doesn't tell you the offending file! Workaround: don't put weird things in string args to cpp macros.