curly brace escaping does not work.

[Anvil]

Curly braces cannot be escaped properly in backticks expressions.

If i try in the tox.ini to set an expression such

setenv =
    VERSION = `echo "\{a\}"`

That leads to a tox.exception.ConfigError: ConfigError: substitution key 'a' not found

I've also tried to double the backslash (\\{) and in that case the substitution is not performed but a '{' is passed to the command, which is inconsistent.

[jayvdb]

@Anvil thanks for raising this. It turns out to be an upstream issue in tox 3.20+ tox-dev/tox#1690 . You can avoid this by using tox 3.19.0 until we've determine how tox core is going to proceed, and if necessary I add a workaround if they have decided to keep the new behaviour.

[jayvdb]

I believe I fixed this upstream @Anvil . Could you confirm that? (And GitHub star my obscure little tool if it is helping you ... :)

btw, #17 fixes a recent breakage with tox - fix for that will be merged soon.

[Anvil]

Thank you for your work. We'll test this as soon as we can.