strange behavior with ImmutableWriter::isExternallyDefined()

[Cyrille37]

Hi

• In a terminal on linux with php 8.3
• the default Php ini has variables_order = "GPCS" ('E' is not present) so the shell env is not present/copied in php $_ENV.
• use of $dotenv = Dotenv::createImmutable('.'); $res = $dotenv->load();

If I export a shell env variable "TOTO" then the "TOTO" entry in the .env file is not read because ImmutableWriter::isExternallyDefined() determine that the variable is externally defined.

Finaly I cannot access "TOTO" value which is set in shell env and in .env file.

Isn't this behaviour strange?