Rollup merge of rust-lang#139285 - tshepang:uniform-case, r=jieyouxu

use lower case to match other error messages

Author: Zalathar

compiler/rustc_session/src/config.rs

@@ -1427,10 +1427,12 @@ pub fn build_target_config(
             }
             target
         }
-        Err(e) => early_dcx.early_fatal(format!(
-            "Error loading target specification: {e}. \
-                     Run `rustc --print target-list` for a list of built-in targets"
-        )),
+        Err(e) => {
+            let mut err =
+                early_dcx.early_struct_fatal(format!("error loading target specification: {e}"));
+            err.help("run `rustc --print target-list` for a list of built-in targets");
+            err.emit();
+        }
     }
 }
 

compiler/rustc_target/src/spec/mod.rs

@@ -3516,7 +3516,7 @@ impl Target {
                     Err("the `i586-pc-windows-msvc` target has been removed. Use the `i686-pc-windows-msvc` target instead.\n\
                         Windows 10 (the minimum required OS version) requires a CPU baseline of at least i686 so you can safely switch".into())
                 } else {
-                    Err(format!("Could not find specification for target {target_tuple:?}"))
+                    Err(format!("could not find specification for target {target_tuple:?}"))
                 }
             }
             TargetTuple::TargetJson { ref contents, .. } => {

tests/run-make/target-specs/rmake.rs

@@ -14,7 +14,7 @@ fn main() {
         .input("foo.rs")
         .target("my-invalid-platform.json")
         .run_fail()
-        .assert_stderr_contains("Error loading target specification");
+        .assert_stderr_contains("error loading target specification");
     rustc()
         .input("foo.rs")
         .target("my-incomplete-platform.json")

tests/ui/errors/wrong-target-spec.rs

@@ -7,4 +7,4 @@
 
 fn main() {}
 
-//~? ERROR Error loading target specification: Could not find specification for target "x86_64_unknown-linux-musl"
+//~? ERROR error loading target specification: could not find specification for target "x86_64_unknown-linux-musl"

tests/ui/errors/wrong-target-spec.stderr

@@ -1,2 +1,4 @@
-error: Error loading target specification: Could not find specification for target "x86_64_unknown-linux-musl". Run `rustc --print target-list` for a list of built-in targets
+error: error loading target specification: could not find specification for target "x86_64_unknown-linux-musl"
+  |
+  = help: run `rustc --print target-list` for a list of built-in targets