Stop mentioning internal lang items in no_std binary errors

When writing a no_std binary, you'll be greeted with nonsensical errors
mentioning lang items like eh_personality and start. That's pretty bad
because it makes you think that you need to define them somewhere! But
oh no, now you're getting the `internal_features` lint telling you that
you shouldn't use them! But you need a no_std binary! What now?

No problem! Writing a no_std binary is super easy. Just use panic=abort
and supply your own platform specific entrypoint symbol (like `main`)
and you're good to go. Would be nice if the compiler told you that,
right?

This makes it so that it does do that.

1 files changed, 6 insertions, 0 deletions

diff --git a/tests/ui/no_std/no-std-no-start-binary.stderr b/tests/ui/no_std/no-std-no-start-binary.stderr
new file mode 100644
index 00000000000..dd06c234da2
--- /dev/null
+++ b/tests/ui/no_std/no-std-no-start-binary.stderr
@@ -0,0 +1,6 @@
+error: using `fn main` requires the standard library
+   |
+   = help: use `#![no_main]` to bypass the Rust generated entrypoint and declare a platform specific entrypoint yourself, usually with `#[no_mangle]`
+
+error: aborting due to 1 previous error
+