[Agda-dev] Mysteries of the GHC recompilation checker

[Andreas Abel]

Do you also see the "missing old dependency" for exactly two files when 
you recompile Agda?  (Mac, GHC 8.10.2)

[201 of 386] Compiling Agda.Interaction.Base ( 
src/full/Agda/Interaction/Base.hs, 
dist-2.6.2-ghc-8.10.2/build/Agda/Interaction/Base.o, 
dist-2.6.2-ghc-8.10.2/build/Agda/Interaction/Base.dyn_o ) [missing old 
dependency]

[349 of 386] Compiling Agda.TypeChecking.Rules.Builtin ( 
src/full/Agda/TypeChecking/Rules/Builtin.hs, 
dist-2.6.2-ghc-8.10.2/build/Agda/TypeChecking/Rules/Builtin.o, 
dist-2.6.2-ghc-8.10.2/build/Agda/TypeChecking/Rules/Builtin.dyn_o ) 
[missing old dependency]

Agda.Interaction.Base and Agda.TypeChecking.Rules.Builtin are always 
recompiled on my machine.  Luckily, this is not infective, files 
depending on these are not recompiled.

Any explanation for this phenomenon?

-- 
Andreas Abel  <><      Du bist der geliebte Mensch.

Department of Computer Science and Engineering
Chalmers and Gothenburg University, Sweden

andreas.abel at gu.se
http://www.cse.chalmers.se/~abela/