rust: add warning_level=0 to downloaded Cargo subprojects

This adds --cap-lints allow, matching how Cargo builds them.  In the case of
Cargo, this is only applied to non-path dependencies.

Without this change, clippy will complain about dependencies as well.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/docs/markdown/snippets/cargo_cap_lints.md b/docs/markdown/snippets/cargo_cap_lints.md
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+## `--cap-lints allow` used for Cargo subprojects
+
+Similar to Cargo itself, all downloaded Cargo subprojects automatically
+add the `--cap-lints allow` compiler argument, thus hiding any warnings
+from the compiler.
+
+Related to this, `warning_level=0` now translates into `--cap-lints allow`
+for Rust targets instead of `-A warnings`.