Thank you all for your inputs and suggestions!
you could try to debug with java -zero / javac -J-zero on amd64.
Done! [1] Unfortunately, I don't see anything useful there but perhaps one of you will.
It selects the "Zero" VM, which I assume is the one used on mips64el.
https://openjdk.java.net/projects/zero/
Ah, thanks for the explanation! It helped me to appropriately adjust build-depends. Hmm, it looks like Zero is not supported on MIPS at the moment, but perhaps that site is just out-of-date?
This seems to indicate that the isDirectory call [4] is getting wrong
file attributes. Following the trail, those file attributes come from
a fstatat call [5] which ultimately come from the native stack in
UnixNativeDispatcher.c [6]. The actual way that fstatat is called
depends on the build flags and defines from the arch, so somebody with
better knowledge might want to take a look at UnixNativeDispatcher.c
[6] and tell if OpenJDK is picking the right function to call for
mips64el.
Thanks for the excellent analysis! So is this indeed a bug in OpenJDK on mips64el then? I'm happy to file the bug, referencing all of the information in this thread, if that's the probable culprit here.
-Olek