[Proposal] restrict mujoco version for "mujoco environments" (v4+)

[Kallinteris-Andreas]

Proposal

mujoco v4 environments support: "2.1.5" <= mujoco.__version__ <= "2.3.3"
mujoco v5 environments (will) support: "2.3.3" <= mujoco.__version__
and it is a good long term solution to pin mujoco==2.3.3

and so a restriction should be added to prevent making a mujoco-v4 environment with an unsupported version of mujoco
e.g. gym.make("Hopper-v4") # with mujoco==2.3.5

a possible implementation would be to add something like to all the v4 environments

if "2.1.5" <= mujoco.__version__ <= "2.3.3":
    generate_error....  # tell the user to `pip instal mujuco==2.3.3`

There may be a better way to implement this. (Perhaps in registration?)

Motivation

No response

Pitch

No response

Alternatives

generate a warning instead of an error

Additional context

No response

Checklist

• I have checked that there is no similar issue in the repo

[pseudo-rnd-thoughts]

Yes, for now, we have pinned the mujoco version for the CI to avoid this issue
But I think your plan is a good idea

[Kallinteris-Andreas]

We would have to skip CI for mujoco-v4 environments if an incompatible version of mujoco was installed, what would be the best way to do that?

[pseudo-rnd-thoughts]

An elegant way, not way. We have a mujoco_envs variable I believe we could modify or we could add a skipIf for certain environment id

[Kallinteris-Andreas]

issue has been fixed with: #589

[Longyouyuan]

hi, how to pin the mujoco to 2.3.3? just input pip install mujoco==2.3.3?

[Kallinteris-Andreas]

yes