The --printf argument to stat does not seem to correctly support precision specifiers in format strings.

For example, after creating a file with touch f...

GNU stat:

$ stat --printf='%.1Y\n' f
1646795086.4

uutils stat:

$ ./target/release/stat --printf='%.1Y\n' f
1

From the documentation

The ‘%W’, ‘%X’, ‘%Y’, and ‘%Z’ formats accept a precision preceded by a period to specify the number of digits to print after the decimal point. For example, ‘%.3X’ outputs the access timestamp to millisecond precision. If a period is given but no precision, stat uses 9 digits, so ‘%.X’ is equivalent to ‘%.9X’. When discarding excess precision, timestamps are truncated toward minus infinity.

-- https://www.gnu.org/software/coreutils/manual/html_node/stat-invocation.html

Edit: this is causing a test failure in the GNU test file tests/stat/stat-nanoseconds.sh.