[GHC] #3226: please eliminate error message from Make on every build

[GHC]

#3226: please eliminate error message from Make on every build
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    Reporter:  nr                |        Owner:                  
        Type:  feature request   |       Status:  new             
    Priority:  normal            |    Milestone:                  
   Component:  Build System      |      Version:  6.11            
    Severity:  minor             |   Resolution:                  
    Keywords:                    |   Difficulty:  Unknown         
    Testcase:                    |           Os:  Unknown/Multiple
Architecture:  Unknown/Multiple  |  
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Comment (by simonmar):

 Replying to [comment:10 nr]:
 > Replying to [comment:9 simonmar]:
 >
 >   Surely most of the time the dependency file will be there anyway?
 >
 > Actually no.  The problem is that I'm propagating a change in the
 representation of low-level intermediate code, and it will be a very long
 time before all the modules in the compiler are once again mutually
 consistent.  And apparently as long as any module does not compile, GHC
 cannot generate the dependency file.  I hope I am wrong about this and am
 just doing something stupid.  Please say I am?

 If I touch a source file in the compiler and then say `make 1` (in
 `compiler/`), I don't see the error message.  Even if I just say `make` in
 `compiler`, which rebuilds the dependencies if anything is out of date, I
 still don't see the error message.

 If you start from a position where you don't have the dependency file,
 then you do need to get to a state where all the imports exist in order to
 build the dependencies (the dependency-generator parses each source file
 up the end of the imports, so errors further down won't affect it).

 > If I'm not doing something stupid, can you suggest where I might go to
 filter the output of make in my own private world?

 In the top-level `Makefile`, something like this:
 {{{
         @echo "===--- finished updating makefiles"
         $(MAKE) -r --no-print-directory -f ghc.mk $@  | sed 'd/.depend: No
 such file or directory/'
 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3226#comment:11>
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