small changes, long build time

David Holmes david.holmes at
Sat Apr 30 07:32:44 UTC 2016

On 30/04/2016 4:18 PM, Alan Bateman wrote:
> On 30/04/2016 00:46, Pete Brunet wrote:
>> Even small edits to code in the jdk source tree result in very long time
>> build times now that jigsaw is merged in.  Is anyone working on trying
>> to improve that?  Is there a workaround?
> When you touch code in a module then you can use "make <module>" to just
> rebuild that module. If you use "make" then it will rebuild that module
> and all other modules that directly or transitively depend on it. There
> are some tricks with sjavac but that is essentially it.
> So which module are you changing? Is this Windows? Are you re-building
> images each time?
> If you are re-building images every time then you'll see it creates the
> jmods (packaged modules too). It is a bit expensive at moment, partly
> because each package module generates hashes of the module artifact of
> each dependency. This has been changed in an upcoming refresh so that
> the hashes are generated and recorded once, this in turn allows for more
> concurrency when generating the packaged modules. This may help you, but
> hard to say.

Just to add my concerns here, I was changing the launcher and building 
images and that caused the jmods to be rebuilt as well. I would not 
expect that so do we have missing dependency information in the build?


> -Alan

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