Setup cargo environment for cargo rustc --print

src/cargo/ops/cargo_compile/mod.rs

@@ -41,7 +41,7 @@ use std::sync::Arc;
 
 use crate::core::compiler::unit_dependencies::build_unit_dependencies;
 use crate::core::compiler::unit_graph::{self, UnitDep, UnitGraph};
-use crate::core::compiler::{standard_lib, CrateType, TargetInfo};
+use crate::core::compiler::{apply_env_config, standard_lib, CrateType, TargetInfo};
 use crate::core::compiler::{BuildConfig, BuildContext, BuildRunner, Compilation};
 use crate::core::compiler::{CompileKind, CompileMode, CompileTarget, RustcTargetData, Unit};
 use crate::core::compiler::{DefaultExecutor, Executor, UnitInterner};
@@ -188,6 +188,7 @@ pub fn print<'a>(
         }
         let target_info = TargetInfo::new(gctx, &build_config.requested_kinds, &rustc, *kind)?;
         let mut process = rustc.process();
+        apply_env_config(gctx, &mut process)?;
         process.args(&target_info.rustflags);
         if let Some(args) = target_rustc_args {
             process.args(args);

tests/testsuite/rustc.rs

@@ -794,6 +794,46 @@ windows
         .run();
 }
 
+#[cargo_test]
+fn rustc_with_print_cfg_config_toml_env() {
+    let p = project()
+        .file("Cargo.toml", &basic_bin_manifest("foo"))
+        .file(
+            "targets/best-target.json",
+            r#"{
+  "llvm-target": "x86_64-unknown-none",
+  "target-pointer-width": "64",
+  "data-layout": "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128",
+  "arch": "x86_64"
+}"#,
+        )
+        .file(
+            ".cargo/config.toml",
+            r#"
+[build]
+target = "best-target"
+[env]
+RUST_TARGET_PATH = { value = "./targets", relative = true }
+"#,
+        )
+        .file("src/main.rs", r#"fn main() {} "#)
+        .build();
+
+    p.cargo("rustc -Z unstable-options --print cfg")
+        .masquerade_as_nightly_cargo(&["print"])
+        .with_stdout_data(
+            str![[r#"
+debug_assertions
+target_arch="x86_64"
+target_endian="little"
+target_pointer_width="64"
+...
+"#]]
+            .unordered(),
+        )
+        .run();
+}
+
 #[cargo_test]
 fn precedence() {
     // Ensure that the precedence of cargo-rustc is only lower than RUSTFLAGS,