Auto merge of #2744 - RalfJung:json, r=RalfJung

support using a JSON target file

Fixes #2053

Author: bors

Cargo.lock

@@ -18,7 +18,7 @@ directories = "4"
 rustc_version = "0.4"
 serde_json = "1.0.40"
 cargo_metadata = "0.15.0"
-rustc-build-sysroot = "0.4"
+rustc-build-sysroot = "0.4.1"
 
 # A noop dependency that changes in the Rust repository, it's a bit of a hack.
 # See the `src/tools/rustc-workspace-hack/README.md` file in `rust-lang/rust`

cargo-miri/Cargo.lock

@@ -137,9 +137,11 @@ pub fn setup(subcommand: &MiriCommand, target: &str, rustc_version: &VersionMeta
         .rustflags(rustflags)
         .cargo(cargo_cmd)
         .build_from_source(&rust_src)
-        .unwrap_or_else(|_| {
-            if only_setup {
-                show_error!("failed to build sysroot, see error details above")
+        .unwrap_or_else(|err| {
+            if print_sysroot {
+                show_error!("failed to build sysroot")
+            } else if only_setup {
+                show_error!("failed to build sysroot: {err:?}")
             } else {
                 show_error!(
                     "failed to build sysroot; run `cargo miri setup` to see the error details"

cargo-miri/Cargo.toml

@@ -108,8 +108,9 @@ case $HOST_TARGET in
     MIRI_TEST_TARGET=i686-pc-windows-msvc run_tests
     MIRI_TEST_TARGET=x86_64-unknown-freebsd run_tests_minimal hello integer vec panic/panic concurrency/simple atomic data_race env/var
     MIRI_TEST_TARGET=aarch64-linux-android run_tests_minimal hello integer vec panic/panic
-    MIRI_TEST_TARGET=wasm32-wasi MIRI_NO_STD=1 run_tests_minimal no_std # supports std but miri doesn't support it
+    MIRI_TEST_TARGET=wasm32-wasi run_tests_minimal no_std # supports std but page_size fails to build
     MIRI_TEST_TARGET=thumbv7em-none-eabihf MIRI_NO_STD=1 run_tests_minimal no_std # no_std embedded architecture
+    MIRI_TEST_TARGET=tests/avr.json MIRI_NO_STD=1 run_tests_minimal no_std # JSON target file
     ;;
   x86_64-apple-darwin)
     MIRI_TEST_TARGET=mips64-unknown-linux-gnuabi64 run_tests # big-endian architecture