[Bug]: Cannot run posix wrappers without setup

[BMBurstein]

Is there an existing issue for this?

• I have searched existing issues

Bug Type

• Firmware
• Tool
• Unit Test

What packages are impacted?

BaseTools

Which targets are impacted by this bug?

No response

Current Behavior

Calling some of the Posix wrappers (e.g. GenSec) from a shell where edksetup.sh was not run and not from within the Posix wrapper directory fails since it cannot find GenericShellWrapper

Expected Behavior

This used to work before #11757 (specifically commit f39883e)

Steps To Reproduce

Open a new terminal session.
Navigate to Edk2 root folder
run ./BaseTools/BinWrappers/PosixLike/GenSec

Build Environment

- OS(s): any Posix
- Tool Chain(s): N/A

Version Information

Commit: f39883ea115f4aef8fe1df4b83b9c33439deca33

Urgency

Low

Are you going to fix this?

I will fix it

Do you need maintainer feedback?

No maintainer feedback needed

Anything else?

No response