a mksandbox annoyance

Kia ora koutou,
Now that I am making more use of mksandbox there is one thing about it 
that I find immensely annoying.

The pkgsrc mountpoint inside the sandbox is not /usr/pkgsrc, but is 
instead a directory with the same name as the pkgsrc directory that 
mksandbox was built in and you can't change it. I have quite a few 
checked out copies of pkgsrc and I really don't want to have to remember 
which one I happened to have built mksandbox in.

e.g. on the two boxes I build on most frequently I have these pkgsrc 
directories

/home/lloyd/NetBSD/cvs/2026-01-10/pkgsrc
/home/lloyd/NetBSD/cvs/trunk/pkgsrc
/home/lloyd/NetBSD/cvs/cartographer/pkgsrc
/home/lloyd/NetBSD/cvs/cross-compilers/pkgsrc
/vol/source/cvs/2026-01-10/pkgsrc
/vol/source/cvs/trunk/pkgsrc
/vol/source/cvs/cartographer/pkgsrc

I don't want to have to remember or type those long names when working 
inside the sandbox.

mksandbox has an option (--pkgsrc) to specify the target of the null 
mount but no option to specify the mountpoint itself.

It seems to me that hard coding /usr/pkgsrc as the mountpoint would have 
been a simpler and more reliable design choice, but that horse has bolted.

Maybe we could add an option --usr-pkgsrc=[dir] that sets the sandbox 
pkgsrc mountpoint to be /usr/pkgsrc or dir if specified? I must admit 
that I'm not in love with the mnemonic properties of that option name 
but I'm running out of ideas.

Any thoughts anyone?

Ngā mihi,
Lloyd