Can't mount /mnt/acme
I tend to create a lot of clones of the Inferno repository when experimenting with Inferno. Some of these are related to tests I was doing when I was trying to write a set of scripts to build an installation disk image for PCs. Others are related to native ports, such as the Raspberry Pi port, ones I've attempted, or those other people did some time ago. (An incomplete list of ports can be found here.)
When I build Inferno for some use, I go through the usual steps of configuring, building mk then running mk install, typically in the repository itself. Running emu works fine, and wm/wm also starts up in the hosted environment, though there are always warnings in the log. These usually mention a missing /usr/david/lib/plumbing file (since my user is called david) and more warnings appear when some applications are started. It helps to copy the existing /usr/inferno/lib/plumbing file into the corresponding place in my home directory, but Acme can't run the Limbo compiler on source files.
The trick to solving this appears to be to run mk in the host environment with the correct rule for the shell you are using. So, on Linux, running mk mkdirs-sh seems to create all the missing directories.
Update: Running mk mkdirs should generally work on any supported platform.