environment: Report "command not found" from the child process.

Fixes a bug whereby, for example:

  guix shell bash -- bash -c xyz

would erroneously print:

  guix shell: error: bash: command not found

simply because the parent process could not distinguish that 127 from a
"genuine" 127 used by convention for "command not found".

* guix/scripts/environment.scm (launch-environment): Before exiting,
report a "command not found" error and suggest a command name.
(validate-exit-status): Remove.
(launch-environment/fork): Remove call
(launch-environment/container)[exit/status*]: Remove.
Call 'exit/status' instead of it.

0 files changed, 0 insertions, 0 deletions