It seems that BeEquivalentTo() doesn't ignore case when comparing strings on Linux environment.

"SomeString".Should().BeEquivalentTo("somestring");

Expected: verification passes.

It works as expected on Windows, but throws but "SomeString" differs near "Som" (index 0) exception on Linux.

On the same environment string assertion from NUnit framework works as expected.

StringAssert.AreEqualIgnoringCase("SomeString", "somestring");

Info:

• FluentAssertions v5.7.0
• .netcoreapp 2.1