Should configure fail if pkg-config fails?

[Jordi Gutiérrez Hermoso]

Today while trying to build the Emacs 24 alpha, I discovered that I
had messed up some things in my local Debian system and pkg-config was
failing. I didn't notice this until I was well into the build system.
The configure script didn't immediately report that something was
wrong, and didn't exit with nonzero status.

Shouldn't the configure script emit a clear warning if pkg-config fails?

Thanks,
- Jordi G. H.