Problem: After bump to 7.3, quick install fails a lot

[clacke]

In particular it seems to fail for some packages depending on scheme-lib. This makes builds very slow, many times slower.

Quick install fails when you try to build foo, which depends on bar, but when you do setup on foo, it tries to recompile some files in bar, even though bar is already compiled.

PLT_COMPILED_FILE_CHECK = "exists"; does not make this go away.

[clacke]

It's not every package depending on scheme-lib. E.g. r5rs-lib is fine.