javac: error: Cannot resolve module dependencies using Jigsaw module resolver

[Jonathan Gibbons]

On 05/19/2010 05:13 AM, Alan Bateman wrote:
> Jon - I've been using the updated javac and it works very well except 
> for the diagnostics. When attempting to compile a module and a 
> dependency that cannot be resolved then the output isn't very 
> informative. I find that I need to set JIGSAW_TRACE to reveal the 
> problem. I realize this is an issue with jmod install too, but I 
> thought I should point it out as an area that probably needs works.
>
> -Alan.

Alan,

Thanks, yes, I am aware of the shortcomings of the diagnostics when 
javac fails to resolve module dependencies.

Currently, javac is just forwarding, as best it can, the information it 
is receiving from the Jigsaw module resolver.   Currently, the error 
reporting channel consists of two possible exceptions (error, and IO 
error) each of which just has a simple detail message for additional detail.

Any improvements need to come from within the Jigsaw module resolver. It 
would help to have more detailed exceptions, that provide more 
information about the error that has detected -- such as the nature of 
the error and the modules or parts of the modules in question.

The hardest part for javac is going to be linking it back to source code 
for those modules in question that were provided in source. The modules 
being analyzed by the module resolver have no direct link back to any 
source code; however, some time ago, Mark and I briefly discussed a way 
of identifying abstract positions within the module info file that javac 
could potentially map back into source positions. But, any improvements 
would have to be part of a bigger campaign to improve the error 
reporting from the Jigsaw module resolver.

-- Jon