unexpected argument '--container-cmd' found

[leecannon]

I'm trying to build edk2-stable202602 and it fails (full log).

Excerpt:

   Compiling xtask v0.0.0 (/home/runner/work/ovmf-prebuilt/ovmf-prebuilt/xtask)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 24.09s
     Running `target/debug/xtask --container-cmd=docker --create-release edk2-stable202602-r1`
error: unexpected argument '--container-cmd' found
Usage: xtask <COMMAND>
For more information, try '--help'.
Error: Process completed with exit code 2.