[com.google.fonts/check/ftxvalidator_is_available] ftxvalidator not available warning despite binary

Observed behaviour

After a bunch of trouble getting ftxvalidator installed I can confirm it is installed by calling the binary. Calling fontbakery consequently still complains about missing ftxvalidator.

ftxvalidator build 207, FontToolbox.framework build 335
Usage:  ftxvalidator [-hlrSTvV] [-t testList] [-o outputfile] fontfile
Options:
	-e An optional list of tests to exclude
	-h Output this message
	-K (--check-build-number) Check that the tool is at least the given version
		`ftxvalidator-K 200` returns -1 if the build number is not 200 or higher
	-l List available tests
...
$ fontbakery check-googlefonts AnyFont.ttf
...
 >> com.google.fonts/check/ftxvalidator_is_available
    Is the command `ftxvalidator` (Apple Font Tool Suite) available?


      Rationale:
      There's no reasonable (and legal) way to run the command `ftxvalidator`
      of the Apple Font Tool Suite on a non-macOS machine. I.e. on GNU+Linux or
      Windows etc.

      If Font Bakery is not running on an OSX machine, the machine running Font
      Bakery could access `ftxvalidator` on OSX, e.g. via ssh or a remote
      procedure call (rpc).

      There's an ssh example implementation at:
      https://github.com/googlefonts/fontbakery/blob/master/prebuilt/workarounds/ftxvalidator/ssh-implementation/ftxvalidator

    * WARN: ftxvalidator is not available.

    Result: WARN

Expected behaviour

Perform ftxvalidator checks.

Resources and exact process needed to replicate

Not sure how to reproduce it aside from simply running the above commands in my setup. Happy to help debug this further.

[kontur]

Yes, nice of you to see it that way, I hope the improvements you made to the detection mechanism prompted by this report are still useful; should have probably tried to narrow down more what could be the cause 👍 TIL shutil has a which command 😉

[kontur]

Ah 🤦 Had ~/bin in my PATH, which resolves in the shell when called, but not for which.