I’ve been exploring making a basic tool to launch scripts based on this specification, plus a non-standard x-requires-python block that gets used with ‘pyenv’ or ‘py’ to find the appropriate python executable. (I probably won’t make it build the appropriate Python with pyenv if it’s missing, but I may make it output the command you would need).
With respect to a proposed TOML based format from a merged proposal I’d note that despite implementing this in Python I’ve tried to make the time from start to running a script when a cached venv can be used as fast as possible[1] and just by importing a toml parser library this takes twice as long before doing any parsing[2]. This probably doesn’t matter if you’ve decided to implement such a thing in rust, and you may consider the overall time to still be small enough not to care, but I did want to point it out.