An element that is never removed (directly or via inheritance) is not allowed to provide the legacy argument to the @available attribute:
{% include “docs/reference/fidl/language/error-catalog/label/_bad.md” %}
{% includecode gerrit_repo="fuchsia/fuchsia" gerrit_path="tools/fidl/fidlc/tests/fidl/bad/fi-0182.test.fidl" exclude_regexp="\/\/ (Copyright 20|Use of|found in).*" %}
Instead, remove the legacy argument:
{% include “docs/reference/fidl/language/error-catalog/label/_good.md” %}
{% includecode gerrit_repo="fuchsia/fuchsia" gerrit_path="tools/fidl/fidlc/tests/fidl/good/fi-0182-a.test.fidl" exclude_regexp="\/\/ (Copyright 20|Use of|found in).*" %}
Alternatively, keep the legacy argument but add the removed argument:
{% include “docs/reference/fidl/language/error-catalog/label/_good.md” %}
{% includecode gerrit_repo="fuchsia/fuchsia" gerrit_path="tools/fidl/fidlc/tests/fidl/good/fi-0182-b.test.fidl" exclude_regexp="\/\/ (Copyright 20|Use of|found in).*" %}
The legacy argument indicates whether an element should be added back at the LEGACY version after being removed, so it doesn't make sense to use it on an element that is never removed. See the documentation on legacy for more details.
