[tlbuild] Maintaining 'custom' installations

[Angelo Graziosi]

Suppose I build current trunk TL2010/dev on Cygwin, and install it with

.../install -custom-bin ...

then how can I maintain the installation, i.e. upgrading it?

In principle that should be done with

tlmgr update -list
tlmgr update -all

but are we sure that the *i386-cygwin* bin/scripts packages will not be 
installed overwriting the 'custom' ones?

Perhaps do we need a 'custom-bin' options also for 'tlmgr'?

Thanks,
Angelo.