[Scons-users] Jar builds fail with SConscript variant directory

[Dirk Bächle]

Hi Bill,

On 01.05.2014 17:52, William Roberts wrote:

> Ok trying again on the right list with the attachment...

>

> I typically set up my builds with a hierachical layout and a variant

> directory and do some other things to make it all work together.

> Normally I program in C, and this all works.

>

> Recently, I tried using java and broke. I have a very simple example

> that doesnt work. If I change the SConscript calls to use a variant

> dir, its broken, if I dont it works...

>

> Sconstruct:

>

>       <snip>

>          SConscript(script)

>          #SConscript(script, variant_dir=outdir, duplicate=1)

>       <snip>

>

> to

>       <snip>

>          #SConscript(script)

>          SConscript(script, variant_dir=outdir, duplicate=1)

>       <snip>

>

> it breaks...

>

> Can someone explain what's going on here? Thanks.


I also tried my luck and had a short look at your build setup. In your 
SConscript you have:

   Java("classes", ".")
   Jar("myjar.jar", "classes")

which works fine as long as you don't use variant dirs. The problem is 
the first line, which creates a dependency between "classes" and ".". 
These are both Dir nodes, so when the VariantDir stuff jumps in and 
starts to copy things, it won't pick up the "*.java" source files living 
*under* the "." directory. You can check this with calling "scons 
--tree=derived", which won't show any "*.java" files as leaves in the 
dependency tree, as one might expect.

A possible way out is to compile the Java files one at a time. This 
requires to additionally set the "-classpath" option, and a proper 
SConscript for your situation would be:

   Java("classes", Glob("*.java"), JAVACLASSPATH=Dir("classes"))
   Jar("myjar.jar", "classes")

This works for duplicate=1, as well as duplicate=0.

Best regards,

Dirk