linux - Make isolated build or any shell command -

please, give me hint simplest , lightest solution isolate linux shell script (usually ubuntu in case has smth special)

what mean isolation: 1. filesystem - important - want cannot access folders (read) outside workspace except manually configure in way 2. actually, other types of isolation not matter

it ok "soft" isolation, mean script may fail/aborted if trying access(read) denied paths, "hard" isolation "not found" such attempts looks cleaner solution

i not need process isolations, script may use sudo/fakeroot/etc. inside it, should not affect isolation.

also, plan use different isolations inside 1 workspace:

for ex., have folders:

a/ b/ include/ target/ 

i want make a giving access "a"(rw), "include"(r) , "target" (rw+sudo) make b giving access "b"(rw), "include"(r) , "target" (rw+sudo)

and target both results , b, allowing b overwrite of results of - same if there no isolation

the target of isolation i'm talking prevent b reading a, knowing there , vice versa

thanks!

two different users , ssh simple way solve problem. 1 of key benefits start "clean" environment in new shell.

ssh <user_a>@localhost '<path_to_build_script_a>' ssh <user_b>@localhost '<path_to_build_script_b>' 

user , b must both members of group owns common directories.

note it's directory write permission decide if user can create new files inside directory.

edit: 2013-07-29

for lots of sequential isolated builds in case, 1 solution have suggested; automate file permission changes each build have access files , folders should.