Fix other "lib binary paths"

[konsolebox]

The fix in cd9daf3 seems not enough since the .so file is still copied to an extra folder in the stage directory. This file tasks created are also not right.

[kou]

Could you show how to reproduce the problem?

[konsolebox]

Using this output in Appveyor as an example you can see in line 1635 that the file is being copied to tmp/i386-mingw32/stage/lib/digest/digest/kangarootwelve.so. At some point I found the so file existing both lib/digest and lib/digest/digest. I'm not sure how I was able to do it, but I've been playing with lib/digest/kangarootwelve.so being used as a file task dependency.

And of course I've also debugged the variables using puts.

[konsolebox]

Ok so here's a way to demonstrate the issues:

git clone https://github.com/konsolebox/digest-xxhash-ruby.git
cd digest-xxhash-ruby
rake lib/digest/digest/xxhash.so
rake clobber

The command shows three things:

1. tmp/x86_64-linux/digest/xxhash/3.0.2/digest/xxhash.so is copied as tmp/x86_64-linux/stage/lib/digest/digest/xxhash.so instead of tmp/x86_64-linux/stage/lib/digest/xxhash.so.

2. rake lib/digest/digest/xxhash.so is invalid and shouldn't work but it did.

3. After running rake clobber, lib/digest/xxhash.so still exists because rake-compiler listed lib/digest/digest/xxhash.so as a clobber target instead.

Please ignore my earlier comment about lib/digest/digest/<so_file> existing. It probably was caused by me mistakenly installing an older commit of rake-compiler while I was debugging the issue.

[kou]

Thanks.
I understand.

[konsolebox]

Thank you too. 👍