[pxc]

There are a few plugins you can use with oh-my-fish and similar tools, for example `fish-foreign-env`, which provide a command (`fenv`, in this case) which runs a given command in bash and then transfers environment variable changes to the fish environment from which it was called.

It's not bash compatibility, but it is good enough for one-offs and even for many scripts and tools that expect to be sourced in your dotfiles from bash.