Fix Rust installation on CI.

Author: reitermarkus

ci/azure-install-rust.yml

@@ -6,21 +6,26 @@ steps:
 
       if command -v rustup; then
         echo `command -v rustup` `rustup -V` already installed
-        rustup self update
-      elif [ "$AGENT_OS" = "Windows_NT" ]; then
-        curl -sSf -o rustup-init.exe https://win.rustup.rs
-        rustup-init.exe -y --default-toolchain $TOOLCHAIN
-        echo "##vso[task.prependpath]$USERPROFILE/.cargo/bin"
+
+        if brew ls rustup &>/dev/null; then
+          brew upgrade rustup
+        else
+          rustup self update
+        fi
       else
-        curl https://sh.rustup.rs -sSf | sh -s -- -y --default-toolchain $TOOLCHAIN
+        curl -sSL https://sh.rustup.rs | sh -s -- -y --default-toolchain="$TOOLCHAIN" --profile=minimal
         echo "##vso[task.prependpath]$HOME/.cargo/bin"
       fi
     displayName: Install rustup
 
   - bash: |
       set -euo pipefail
-
-      rustup update $TOOLCHAIN
+      rustup set profile minimal
+      rustup component remove --toolchain=$TOOLCHAIN rust-docs || echo "already removed"
+      rustup update --no-self-update $TOOLCHAIN
+      if [ "$TOOLCHAIN" = "nightly" ]; then
+        rustup component add --toolchain=$TOOLCHAIN rustc-dev
+      fi
       rustup default $TOOLCHAIN
     displayName: Install rust