[GHC] #15541: package environment files and the GHC API

[GHC]

#15541: package environment files and the GHC API
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        Reporter:  lspitzner         |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.6.1
       Component:  GHC API           |              Version:  8.4.3
      Resolution:                    |             Keywords:  package
                                     |  environment
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Documentation     |  Unknown/Multiple
  bug                                |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #15513            |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by lspitzner):

 The haddock on `setSessionDynFlags` currently reads:

 > Updates both the interactive and program DynFlags in a Session. This
 also reads the package database (unless it has already been read), and
 prepares the compilers knowledge about packages. It can be called again to
 load new packages: just add new package flags to (packageFlags dflags).
 >
 > Returns a list of new packages that may need to be linked in using the
 dynamic linker (see linkPackages) as a result of new package flags. If you
 are not doing linking or doing static linking, you can ignore the list of
 packages returned.

 I assume this is where package environment files are read.

 So in addition to nothing being documented, this semantic change was made
 to a function with the innocuous name of `setSessionDynFlags`.

 Please don't do that.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15541#comment:3>
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