Refactor with fewer intermediate artifacts

ci/run-travis.sh

@@ -8,9 +8,7 @@ fi
 
 export HOST=$ARCH-$OS
 
-# clang has better error messages and implements alignof more broadly
-export CC=clang
-
+MAIN_TARGETS=https://static.rust-lang.org/dist/
 EXTRA_TARGETS=https://people.mozilla.org/~acrichton/libc-test/2015-09-08
 
 if [ "$TARGET" = "arm-linux-androideabi" ]; then
@@ -26,7 +24,11 @@ elif [ "$TARGET" = "arm-unknown-linux-gnueabihf" ]; then
   sudo apt-get install gcc-4.7-arm-linux-gnueabihf qemu-user
   export CC=arm-linux-gnueabihf-gcc-4.7
 elif [ "$TARGET" = "mips-unknown-linux-gnu" ]; then
+  # Download pre-built and custom MIPS libs and then also instsall the MIPS
+  # compiler according to this post:
+  # http://sathisharada.blogspot.com/2014_10_01_archive.html
   curl -s $EXTRA_TARGETS/$TARGET.tar.gz | tar xzf - -C $HOME/rust/lib/rustlib
+
   echo 'deb http://ftp.de.debian.org/debian squeeze main' | \
     sudo tee -a /etc/apt/sources.list
   echo 'deb http://www.emdebian.org/debian/ squeeze main' | \
@@ -36,13 +38,15 @@ elif [ "$TARGET" = "mips-unknown-linux-gnu" ]; then
   sudo apt-get install qemu-user gcc-4.4-mips-linux-gnu -y --force-yes
   export CC=mips-linux-gnu-gcc
 else
-  # Download and install the relevant target locally, then run tests
-  curl -sO https://static.rust-lang.org/dist/rust-$TRAVIS_RUST_VERSION-$HOST.tar.gz
-  tar xf rust-$TRAVIS_RUST_VERSION-$HOST.tar.gz
-  rm -rf $HOME/rust/lib/rustlib/$HOST
-  mv rust-$TRAVIS_RUST_VERSION-$HOST/rustc/lib/rustlib/$HOST \
-     $HOME/rust/lib/rustlib
+  # Download the rustlib folder from the relevant portion of main distribution's
+  # tarballs.
+  curl -s $MAIN_TARGETS/rust-$TRAVIS_RUST_VERSION-$HOST.tar.gz | \
+    tar xzf - -C $HOME/rust/lib/rustlib --strip-components=4 \
+      rust-$TRAVIS_RUST_VERSION-$HOST/rustc/lib/rustlib/$HOST
   TARGET=$HOST
+
+  # clang has better error messages and implements alignof more broadly
+  export CC=clang
 fi
 
 mkdir .cargo