Auto merge of #5874 - japaric:revert-revert-gh5606, r=alexcrichton

make `cargo install` ignore .cargo/config

closes #5850

r? @alexcrichton

src/bin/cargo/commands/install.rs

@@ -75,6 +75,11 @@ continuous integration systems.",
 
 pub fn exec(config: &mut Config, args: &ArgMatches) -> CliResult {
     let mut compile_opts = args.compile_options(config, CompileMode::Build)?;
+
+    // for `cargo-install` we want to use what the user specified via `--target` and ignore what's
+    // in `.cargo/config` and what the environment says
+    compile_opts.build_config.requested_target = args.target();
+
     compile_opts.build_config.release = !args.is_present("debug");
 
     let krates = args.values_of("crate")

src/doc/src/reference/config.md

@@ -100,7 +100,7 @@ check-revoke = true # Indicates whether SSL certs are checked for revocation
 jobs = 1                  # number of parallel jobs, defaults to # of CPUs
 rustc = "rustc"           # the rust compiler tool
 rustdoc = "rustdoc"       # the doc generator tool
-target = "triple"         # build for the target triple
+target = "triple"         # build for the target triple (ignored by `cargo install`)
 target-dir = "target"     # path of where to place all generated artifacts
 rustflags = ["..", ".."]  # custom flags to pass to all compiler invocations
 incremental = true        # whether or not to enable incremental compilation

tests/testsuite/install.rs

@@ -1237,3 +1237,31 @@ warning: be sure to add `[..]` to your PATH to be able to run the installed bina
 ",
         ).run();
 }
+
+#[test]
+fn install_ignores_cargo_config() {
+    pkg("bar", "0.0.1");
+
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+            [package]
+            name = "foo"
+            version = "0.1.0"
+            authors = []
+        "#,
+        )
+        .file(
+            ".cargo/config",
+            r#"
+            [build]
+            target = "non-existing-target"
+        "#,
+        )
+        .file("src/main.rs", "fn main() {}")
+        .build();
+
+    cargo_process("install bar").cwd(p.root()).with_status(0).run();
+    assert_has_installed_exe(cargo_home(), "bar");
+}