Fix a bug in checkHeader Ignore-this: 4703220c90a9c7c63e6a2872e7b327d5 There was a semantic bug coupled with a layout error that caused this to be more or less overlooked.  The problem was that the `catchC` was indented too far and therefore only applied to the second compilation step, rather than the whole do-block.  The exception handler never re-threw the error, but checkHeader still failed because it was usually the first step in the compilation that failed.  Hence, the files were never deleted.  We might want to do something like bracket instead, to try to be a little safer.
Fix a bug in checkHeader
Ignore-this: 4703220c90a9c7c63e6a2872e7b327d5
There was a semantic bug coupled with a layout error that caused this to
be more or less overlooked.  The problem was that the `catchC` was indented
too far and therefore only applied to the second compilation step, rather
than the whole do-block.  The exception handler never re-threw the error,
but checkHeader still failed because it was usually the first step in the
compilation that failed.  Hence, the files were never deleted.  We might
want to do something like bracket instead, to try to be a little safer.

droundy/franchise