I have a nodejs script that runs a lot of shell commands. In the last few days, script strarted throwing strange errors, but it continued to work.
This was the error on CentOS:
exec: Exec returned error code1

and this on Ubuntu:
exec: Exec returned error code127

When I changed the script dependencies to sue shelljs v0.2.2 the errors stopped appearing.
Note that the errors were only shown when the script was installed with npm, when it was called directly from the local repository there were no errors.