[Scons-users] untar builder fails with error

[Mats Wichmann]

On 11/8/22 08:21, daggs wrote:

> I've decided to debug it on my home setup, it uses scons 4.4.0 and python 3.10.8
> the code I'm using is this: https://dpaste.com/CA5CGYWNC and I'm getting this:
> dagg at NCC-5001D ~/workspace/scons_untar $ scons .
> scons: Reading SConscript files ...
> AttributeError: 'map' object has no attribute 'side_effect':
>    File "/home/dagg/workspace/scons_untar/SConstruct", line 40:
>      thirdPartyEnvironment.UnTar(source="apr-1.3.3")
>    File "/usr/lib/python3.10/site-packages/SCons/Environment.py", line 238:
>      return super().__call__(target, source, *args, **kw)
>    File "/usr/lib/python3.10/site-packages/SCons/Util.py", line 737:
>      return self.method(*nargs, **kwargs)
>    File "/usr/lib/python3.10/site-packages/SCons/Builder.py", line 663:
>      return self._execute(env, target, source, OverrideWarner(kw), ekw)
>    File "/usr/lib/python3.10/site-packages/SCons/Builder.py", line 579:
>      _node_errors(self, env, tlist, slist)
>    File "/usr/lib/python3.10/site-packages/SCons/Builder.py", line 291:
>      if t.side_effect:

In Python 3, the map function returns a map object, which is an 
iterable, not a list. You can iterate over it - which is the usual 
operation - but not otherwise do much with it. You will have to create a 
list out of the result of mapping (we could argue that SCons' logic 
should accept any iterable here but that's a different story).

 >>> x = [1, 2, 3]
 >>> y = map(str, x)
 >>> print(y)
<map object at 0x7ff5e5590d00>
 >>> print(list(y))
['1', '2', '3']


So probably this will help:

newTargets = list(map(tarInfoToNode, tarFileContents))