Test failure with PHP 8.4

[remicollet]

Using 8.4.0beta3

PHPUnit 10.5.30 by Sebastian Bergmann and contributors.

Runtime:       PHP 8.4.0beta3
Configuration: /dev/shm/BUILD/tc-lib-color-14fc157ae64767cc6761e9126f7ec7e5b27bf1cb/phpunit.xml

................................................................. 65 / 94 ( 69%)
F.....................F......                                     94 / 94 (100%)

Time: 00:00.018, Memory: 4.00 MB

There were 2 failures:

1) Test\PdfTest::testGetColorObject
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'#4080bfff'
+'#407fbfff'

/dev/shm/BUILD/tc-lib-color-14fc157ae64767cc6761e9126f7ec7e5b27bf1cb/test/PdfTest.php:154

2) Test\WebTest::testGetColorObj
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'#4080bfff'
+'#407fbfff'

/dev/shm/BUILD/tc-lib-color-14fc157ae64767cc6761e9126f7ec7e5b27bf1cb/test/WebTest.php:191

FAILURES!
Tests: 94, Assertions: 274, Failures: 2.

[nicolaasuni]

Interesting.
At first glance, since this works with all the preceding PHP version since 5, It could be PHP 8.4 bug.
It may be related to the changes in the PHP round function:
php/php-src#14332