A contributor that returns an undeclared key or a non-string value now fails the shell call with ShellEnvError SHELL_ENV_CONTRIBUTION_INVALID instead of a plain Error, with the same message. Refs #7869
A contributor that returns an undeclared key or a non-string value now fails the shell call with ShellEnvError SHELL_ENV_CONTRIBUTION_INVALID instead of a plain Error, with the same message. Refs #7869