message: local rustc builds now also need a sysroot built
  With the test-miri flag gone, the libstd of local builds isn't good enough for Miri any more.
diff: @@ -60,28 +60,20 @@ build_sysroot() {
  # Prepare and set MIRI_SYSROOT. Respects `MIRI_TEST_TARGET` and takes into account
  # locally built vs. distributed rustc.
  find_sysroot() {
  - # Get ourselves a sysroot
  if [ -n "$MIRI_SYSROOT" ]; then
  # Sysroot already set, use that.
  - true
  - elif echo "$SYSROOT" | egrep -q 'build/[^/]+/stage'; then
  - # A local rustc build.
  - if [ -n "$MIRI_TEST_TARGET" ]; then
  - # Foreign targets still need a build. Use the rustc sources.
  + return 0
  + fi
  + # We need to build a sysroot.
  + if echo "$SYSROOT" | egrep -q 'build/[^/]+/stage'; then
  + # A local rustc build. Use its source dir.
  export XARGO_RUST_SRC="$SYSROOT/../../../src"
  - build_sysroot --target "$MIRI_TEST_TARGET"
  - else
  - # Assume we have a proper host libstd in $SYSROOT.
  - MIRI_SYSROOT="$SYSROOT"
  fi
  - else
  - # A normal toolchain. We have to build a sysroot either way.
  if [ -n "$MIRI_TEST_TARGET" ]; then
  build_sysroot --target "$MIRI_TEST_TARGET"
  else
  build_sysroot
  fi
  - fi
  export MIRI_SYSROOT
  }
  