Shading fails with PGF 3.1.7a and ConTeXt LMTX

[jeanprey]

Brief outline of the bug

Shading key words (left color, etc.) aren't recognized with PGF 3.1.7a and ConTeXt.

I have seen the bug report #928 about shadings issue on latex, I don't think this is related.

Minimal working example (MWE)

Here is a minimal failing example

\usemodule[tikz]
\starttext
\starttikzpicture
\node [left color=red, right color=yellow] {Hello};
\stoptikzpicture
\stoptext

The compilation fails with pgf version 3.1.7a and ConTeXt 20201210 LMTX with the following message

tex error on line 4 in file ./mfe-shade.tex: Valid keyword expected, likely 'direction'

(see attached log file).
mfe-shade.log

I tried the same example with the same ConTeXt version and pgf version 3.0.1 which is available in the ConTeXt distribution and it works perfectly well.

[hmenke]

LMTX is radically changing the backend compared to LuaTeX. I hope we can keep compatibility. The offending commit is this one: 74b2cc3