Hi John,
"command" is an bash built-in command and can't be executed by Tcl/Expect directly. With the following small change to the line above your second patch is unnecessary.
if { [catch {set path [exec bash -c "command -v $command"]}] == 0} {
That solved it. I knew it was a silly problem. :^)
could you please give commit [1] a try? The solution is a little bit leaner.
[1] https://github.com/nfeske/genode/commit/b5a604f2463862acc0766090e66e04580fad...
Cheers Norman