Wrong info found: $*

[mjy9088]

The $* macro shall evaluate to the current target name with its suffix deleted. It shall be evaluated at least for inference rules.

• POSIX

Your description The stem that matched the pattern of a rule is wrong.

[mjy9088]

I found GNU Make manual states:

The stem with which an implicit rule matches (see How Patterns Match). If the target is dir/a.foo.b and the target pattern is a.%.b then the stem is dir/foo. The stem is useful for constructing names of related files.
In a static pattern rule, the stem is part of the file name that matched the ‘%’ in the target pattern.
In an explicit rule, there is no stem; so ‘$’ cannot be determined in that way. Instead, if the target name ends with a recognized suffix (see Old-Fashioned Suffix Rules), ‘$’ is set to the target name minus the suffix. For example, if the target name is ‘foo.c’, then ‘$’ is set to ‘foo’, since ‘.c’ is a suffix. GNU make does this bizarre thing only for compatibility with other implementations of make. You should generally avoid using ‘$’ except in implicit rules or static pattern rules.
If the target name in an explicit rule does not end with a recognized suffix, ‘$*’ is set to the empty string for that rule.

I think GNU Make is not POSIX-compliant when Makefile uses %.