[Scons-users] Using Command with TryBuild

[Dirk Bächle]

Carnë,

On 15.02.2013 08:37, Carnë Draug wrote:

> Hi

>

> I'm unable to use the Command builder with TryBuild. I get the following error:

>

> AttributeError: 'NodeList' object has no attribute 'builder':

>    <snip>

>    File "/usr/lib/scons/SCons/SConf.py", line 799:

>      return self.sconf.TryBuild(*args, **kw)

>    File "/usr/lib/scons/SCons/SConf.py", line 546:

>      pref = self.env.subst( builder.builder.prefix )

>

> I'm using this has to check for the availability of a perl module

>

> context.TryBuild (context.env.Command(target = [], source = [], action

> = "perl -M%s -e 1" % module))


please don't use TryBuild or TryAction for these kind of checks. They 
are highly specialised methods, usually working together with the 
Object() or Program() Builders. In your case it makes sense to do the 
check completely on your own. Please, find a first simple version 
attached, based on subprocess. I hope you can put it to good use...

Regards,

Dirk

-------------- next part --------------
import SCons.Builder
import subprocess

def PerlHasModule(context, module):
    res = True
    context.Message('Checking for Perl module %s... ' % module)
    process = subprocess.Popen(['perl','-M%s' % module,'-e','1'], shell=False, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    stdout, stderr = process.communicate()
    status = process.wait()
    
    if status:
        res = False

    context.Result(res)
    return res

env = Environment()
c = env.Configure(custom_tests = {'PerlHasModule' : PerlHasModule})

if c.PerlHasModule('balla'):
    print "Adding defines for Perl module."
else:
    print "Not adding anything for Perl module!"