I don't think this will work. Check what the output of pygmentize -V is in order to be parsed; @epriestley gives examples from T9587#140655:

$ pygmentize -V
Pygments version 2.0.1, (c) 2006-2014 by Georg Brandl.

The version_compare will only be able to parse the 2.0.1 and not any of the rest of the line:
http://php.net/manual/en/function.version-compare.php

You will need to parse the version number out of $stdout prior to using it in version_compare in order for this to be a valid comparison.

This should probably list the existing version of pygmentize found, and the second sentence here might read better if phrased a little differently:

Upgrading pygmentize to version 2.0 or greater can improve performance in syntax highlighting.

I think these upgrade installations are too specific for a setup. Particularly in my case I do not have pip installed. The instructions on /config/edit/pygments.enabled/ indicate:

To install Pygments, visit pygments.org and follow the download and install instructions.

Deferring to installation instructions which pygments itself instructs. The upgrade instructions should probably be similar.

Does this need to reference something or can a new issue identifier be created on-the-spot?

I'm not very familiar with reporting issues in Phabricator - I'm guessing this line adds Phabricator's environment path to the output,and probably useful to display for this purpose.

Sems so : I grep for pygments.failed and only found one entry.

That was also my thought.

I'm not sure what would work best here. Off-hand I think this would fail if one of the version numbers was more than 1 digit:

version 2.0.19

As this regex is looking for single digits. Here's some psuedo-php/regex

// match the output looking for just "version x.x.x", capturing "x.x.x" in the match group
preg_match('/version ([\d|\.]+)/', $stdout, $match);
// strip out the "version ", should do error checking in case nothing matched!
$match[0] = $match[0].substring("version ".length);

That's not correct php but I'm not very familiar with string processing in php and don't have time at the moment to look up the proper way to do it.

Needs a space -> "available. Upgrading"

or (\d+\.\d+\.\d+)

Yea, that's what I was thinking but would need to test. I didn't know if the + would work inside a capture group (). Maybe PHP's version_compare has available a regex it uses internally that we can utilize?

Seems so https://regex101.com/r/sK7sA1/1 !

@epriestley : can I rename this to 'pygments.notfound' ??

Maybe I should not hardcode 2.0.0 and make a variable like $min_perf_version ?

This style issue apart what version should we wait to get @gd improvements in ?

I think it would be 2.1 !

In T9587#140778, @epriestley wrote:

Possibly we should wait until that makes it to a release and specifically recommend the release containing that fix ("Upgrade to 2.0.5 or newer...", or whatever the next release number is) since it's probably the highest-impact user-facing change between 1.4 and today for most users, albeit only for a subset of inputs.

Shall I put on hold till 2.1 appears ?

TODO : Shall be pygments