python3_version fact doesn't work on SCL

[bodgit]

Affected Puppet, Ruby, OS and module versions/distributions

• Puppet: 5.x
• Ruby:
• Distribution: Red Hat
• Module version: 2.2.3-rc0

How to reproduce (e.g Puppet code you use)

Commits 72c34fa and 3d102f4 have added the python3_version fact in the python::pyvenv defined type however this fact doesn't resolve to anything with SCL as the various binaries are not in $PATH by default.

What are you seeing

Various errors along the lines of:

Evaluation Error: Error while evaluating a Resource Statement, Evaluation Error: Error while evaluating a Function Call, 'versioncmp' parameter 'a' expects a String value, got Undef (file: /.../python/manifests/pyvenv.pp, line: 62, column: 9)

What behaviour did you expect instead

If I explicitly set the version parameter for python::pyvenv then I can skip over the first use of the fact here:

puppet-python/manifests/pyvenv.pp

Line 40 in e87db52

'system' => $facts['python3_version'],

But then I still fall foul here:

puppet-python/manifests/pyvenv.pp

Line 62 in e87db52

if (versioncmp($facts['python3_version'], '3.6') >=0) {

It's probably better to use the computed/normalised version string in this call to versioncmp() rather than use the fact again.

$::python::exec_prefix is already set up correctly so after these checks complete the correct SCL-provided python binaries are used.

Output log

Any additional information you'd like to impart

I'll add a fix for this to my existing #472 PR.