[PATCH] debuginfod: print filename for "cannot open archive" error

[Frank Ch. Eigler]

Hi -

> Report the file that has such a problem so that one can inspect it.
> Signed-off-by: Martin Liska <mliska@suse.cz>

The complication with this type of change is that the exception text
objects also make it into the prometheus metrics.  When file names and
such variables show up, they will bifurcate all the affected error
metrics into families.

Not sure what is the best solution to that.  A separate verbose log
print to explain the specifics of this error?  An extra parameter to
the exception object, which is only logged but not passed to
prometheus metric naming?  Some other way?

- FChE