changing exec to always use abs path

lib.go

@@ -239,7 +239,11 @@ func Exec(str string, opts ...*Opts) ([]*exec.Cmd, error) {
 		cmdwd = filepath.Join(wd, cmdwd)
 	}
 	prepCmd := func(l Line) *exec.Cmd {
-		cmd := exec.Command(l.Tokens[0], l.Tokens[1:]...)
+		fqncmd, err := exec.LookPath(l.Tokens[0])
+		if err != nil {
+			fqncmd = filepath.Join(cmdwd, l.Tokens[0])
+		}
+		cmd := exec.Command(fqncmd, l.Tokens[1:]...)
 		cmd.Stdout = log.Writer()
 		cmd.Stderr = log.Writer()
 		cmd.Dir = cmdwd