bug#23969: hard to understand error message

[Vincent Legoll]

Hello,

I'm discovering guix, and started to try to package something.

I made an error (add a string URL parameter to license x11-style):

(license x11-style "file://LICENSE")

But this is not working, because I've forgotten the scheme call syntax
(missing parens)

I'll fix my package definition with:

(license (x11-style "file://LICENSE"))

which seems to be working OK...

But the error message I got was very unhelpful:

something.scm:10:2: warning: source expression failed to match any pattern

the line 10 is:
  (package

whereas the real error happened on line 32 (the license one)

So what's wrong:
- wrong line number
- 'source expression' meaning is shady, as there is a "(source (origin
...))" element defined in the package, which is also not on line 10,
but misleading anyways

I would have expected that error to be reported as:

error: license x11-style: cannot match the pattern : file://LICENSE in
directory /tmp/guix-build-something/something/path/to/where/it/searched

-- 
Vincent Legoll