Is this a bug?
 

The ldd script in Slackware current appears to use /usr/bin/bash as an interpreter. I thought the usual place for bash was /bin, not /usr/bin.

/usr/bin/bash is a symlink to /bin/bash so the interpreter itself is where you expect it to be.

Not here! I had to sort that myself. Maybe that's the bug.

Then I assume this symlink was removed from your system, as it's made when installing the bash package since at least Slackware version 13.37. So if it's a bug it's doesn't come from Slackware.

Ah! That explains it. The bash package was failing some of the tests on shellshocker.net so I made my own patched version that doesn't. That's where the symlink went.