[Scons-users] Debugging scons scripts

[Gary Oberbrunner]

On Wed, Aug 8, 2012 at 11:23 AM, Bjoern Doebel <bjoern.doebel at gmail.com> wrote:

> Hi all,

>

> I'd like to debug a scons setup and would be interested in pointers on

> how to proceed.

>

> I have a setup that builds one library and 2 applications (which

> depend on the lib to be ready) within a variant dir. In general, For

> that I do in my SConstruct:

>

> env = Environment( ... some std. settings for CPPPATH, FLAGS etc. )

> SConscript("app1", variant_dir="#/build/app1", exports="env")

> SConscript("app2", variant_dir="#/build/app2", exports="env")

> SConscript("lib", variant_dir="#/build/lib", exports="env")

>

> In the SConscripts I simply add a bunch of objects and one target:

>

> app1: env.app1 = env.Program("app1", app1_objs)

> app2: env.app2 = env.Program("app2", app2_objs)

> lib:     env.lib     = env.Library("foo", lib_objs)

>

> I declare additional dependencies in my main SConstruct:

>

> env.Depends(env.app1, env.lib)

> env.Depends(env.app2, env.lib)

>

> This setup works fine so far. Now I added some Autoconf-style magic.

> _Before_ calling into the SConscripts, I do:

>

> conf = Configure(env)

> if not conf.CheckCC(): sys.exit(1)

> [... additional stuff ...]

> if not conf.CheckLib("boost_serialization", language="C++"): sys.exit(1)

> env = conf.Finish()

>

> The configuration stuff works as expected as well. Now I'm getting to

> my problem:

>

> When I modify one object that goes into the library, I'd expect the

> object as well as the library and all dependencies to be rebuilt.

> However, scons only triggers a rebuild of the object file, but does

> not link the library or the depending programs. I found this weird, so

> I started investigating. And what I found was, that if I remove the

> conf line:

>

> if not conf.CheckLib("boost_serialization", language="C++"): sys.exit(1)

>

> I get the expected behavior. This is really strange, because the

> boost_serialization lib is not related to the lib I build at all.


Hi Bjorn; start with --tree=prune (and maybe --taskmastertrace=-) to
get a very detailed version of what's going on.

It's possible you're running into
http://scons.tigris.org/issues/show_bug.cgi?id=2757 which I filed a
while ago, but maybe your case is different.