expand keep-stage --help text

diff --git a/src/bootstrap/flags.rs b/src/bootstrap/flags.rs
index 60b4d65f444014133bd81262a7cbdcabea84bdfe..2084b8bdb65ffb859bb74195c6ec764ad4069afc 100644 (file)
--- a/src/bootstrap/flags.rs
+++ b/src/bootstrap/flags.rs
@@ -125,7 +125,8 @@ pub fn parse(args: &[String]) -> Flags {
             "stage to build (indicates compiler to use/test, e.g. stage 0 uses the \
              bootstrap compiler, stage 1 the stage 0 rustc artifacts, etc.)",
             "N");
-        opts.optmulti("", "keep-stage", "stage(s) to keep without recompiling", "N");
+        opts.optmulti("", "keep-stage", "stage(s) to keep without recompiling \
+            (pass multiple times to keep e.g. both stages 0 and 1)", "N");
         opts.optopt("", "src", "path to the root of the rust checkout", "DIR");
         opts.optopt("j", "jobs", "number of jobs to run in parallel", "JOBS");
         opts.optflag("h", "help", "print this help message");