tuned signature;

clarified hg push return code: 1 means "nothing to push";

eliminated extra trim_line: Process_Result.out/err are based on cat_lines, without trailing newline;

more operations;

bash process with builtin timing;

tuned signature;

clarified modules;

proper return code for timeout (amending f868f12f9419);

retain tail out_lines as printed, but not the whole log content;

more informative Build.build_results;
tuned signature;

more informative Process_Result;
tuned;

clarified modules;