Bizarre build problem that goes away when you "make" again.

[Kaz Kylheku]

Solved!

In my build script, I used the obvious name TARGET_ARCH.

Unfortunately, GNU Make's implicit rules also use TARGET_ARCH.

You can quickly uncover that if you run "strings" on /usr/bin/make.

Still, it's hard to understand why the problem went away in one
particular situation.

Think ... think ...

Aha, I got it! I've been doing

  TARGET_ARCH=<asdf> ./build.sh

But that time when the MIPS rebuild worked, I forgot the
assignment. And the variable defaulted to mips-linux inside the
script. Of course, it's not exported by the script. I wouldn't
do anything so stupid as to export random environment
variables which could wreak who knows what havoc. :)