improve performance on WSL2

[musou1500]

This PR fixes performance issue on WSL described in #96

[akinomyoga]

Thank you for looking into this issue. I believe this issue should be fixed in the upstream WSL2, but we probably need to adjust it on our side since they don't seem to be going to fix it.

I'd like to check also [[ :$PATH: == *:/mnt/*:* ]] to determine the use of this workaround because there doesn't seem to be performance degradation as far as /mnt/* is not present in PATH.

[akinomyoga]

I'd like to check also [[ :$PATH: == *:/mnt/*:* ]] to determine the use of this workaround because there doesn't seem to be performance degradation as far as /mnt/* is not present in PATH.

Have you noticed this part?

[musou1500]

thank you. I'll additional check for [[ :$PATH: == *:/mnt/*:* ]].
If my understand is correct, condition will be "using wsl and $PATH includes /mnt".
is it correct?

[akinomyoga]

That's right.

[musou1500]

I made change that checks $PATH and confirmed performance issue is fixed !

[akinomyoga]

Thanks for updating!

[akinomyoga]

I've merged it. Thanks!