Add workaround for rust-lang/rust#74946

Fixes #1072

Author: bjorn3

build_sysroot/build_sysroot.sh

@@ -18,7 +18,8 @@ rm -r sysroot/ 2>/dev/null || true
 export RUSTFLAGS="$RUSTFLAGS -Z force-unstable-if-unmarked"
 if [[ "$1" == "--release" ]]; then
     sysroot_channel='release'
-    RUSTFLAGS="$RUSTFLAGS -Zmir-opt-level=2" cargo build --target $TARGET_TRIPLE --release
+    # FIXME Enable incremental again once rust-lang/rust#74946 is fixed
+    CARGO_INCREMENTAL=0 RUSTFLAGS="$RUSTFLAGS -Zmir-opt-level=2" cargo build --target $TARGET_TRIPLE --release
 else
     sysroot_channel='debug'
     cargo build --target $TARGET_TRIPLE