Do not unconditionally set the target.

guide/src/examples/rustdoc.md

@@ -21,7 +21,7 @@ set -e
 
 cargo doc
 
-grep "some example text" $CARGO_TARGET_DIR/$CARGO_BUILD_TARGET/doc/mycrate/fn.foo.html
+grep "some example text" $CARGO_TARGET_DIR/doc/mycrate/fn.foo.html
 ```
 
 This can be used with the `--script` option:

guide/src/usage.md

@@ -106,6 +106,6 @@ COUNT=`echo "$OUTPUT" | grep -c "unnecessary parentheses"`
 test $COUNT -eq 1
 ```
 
-If you need to use the targets directly without using `cargo` in the script, they are available in `$CARGO_TARGET_DIR/$CARGO_BUILD_TARGET/[release|debug]/...`, since `cargo-bisect-rustc` sets `$CARGO_TARGET_DIR` and `$CARGO_BUILD_TARGET`.
+If you need to use the targets directly without using `cargo` in the script, they are available in `$CARGO_TARGET_DIR/[release|debug]/...`, since `cargo-bisect-rustc` sets `$CARGO_TARGET_DIR`.
 
 Check out the [examples chapters](examples/index.md) for several examples of how to use this option.

src/toolchains.rs

@@ -288,7 +288,6 @@ impl Toolchain {
         };
         cmd.current_dir(&cfg.args.test_dir);
         cmd.env("CARGO_TARGET_DIR", format!("target-{}", self.rustup_name()));
-        cmd.env("CARGO_BUILD_TARGET", &cfg.target);
 
         // let `cmd` capture stderr for us to process afterward.
         let must_capture_output = cfg.args.regress.must_process_stderr();