doc: require StringMaker instead of formatter for test printingfeature/catch2-string-makers

1 files changed, 3 insertions, 4 deletions

diff --git a/CONTRIBUTING.rst b/CONTRIBUTING.rst
index 1ea69ee6..dabc2552 100644
--- a/CONTRIBUTING.rst
+++ b/CONTRIBUTING.rst
@@ -59,10 +59,9 @@ Printing Values in Test Failures
 
 Catch2 prints values it cannot convert as ``{?}``.
 To avoid that, every test translation unit force-includes ``kstd/test_support/string_makers.hpp`` (kstd tests) or ``kernel/test_support/string_makers.hpp`` (kernel tests), which teach Catch2 how to print our types without touching kernel code.
-To make a new type printable in tests, either:
-
-* give it a ``kstd::formatter`` specialization, which is picked up automatically, or
-* add a ``Catch::StringMaker`` specialization to the ``string_makers.hpp`` of the library the type belongs to.
+To make a new type printable in tests, add a ``Catch::StringMaker`` specialization to the ``string_makers.hpp`` of the library the type belongs to.
+Do not add or change anything in kernel code (e.g. a ``kstd::formatter``) just to make a type printable in tests.
+Types that already have a ``kstd::formatter`` are printed through it automatically.
 
 Bootable Kernel Targets
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