guix container with FHS emulation and env vars

[jman]

Hello,

When emulating a FHS I observe that env vars are not preserved. Example
this command will not preserve $PATH:

guix shell --container --emulate-fhs --preserve='^PATH$'

When creating a container *without* emulating a FHS, env vars are available, 
example:

guix shell --container --preserve='^PATH$'

See this log:
https://paste.sr.ht/~jman/65e7f96c445504e11f55595b237280e0c1e3ad34

Any hint? I am a guix newbie so I am sure I am missing something :)

thanks