At which stage in the Emacs startup sequence does the $HOST environment variable become available to Emacs?

I've got an environment variable called $HOST and it seems that Emacs doesn't read it early enough. It usually isn't available during the execution of `init.el` It s present in the environment frm which I run Emacs. `(getenv "HOST")` returns a blank and it is annoying as my `custom-file` includes the `USER` and `HOST` variables so I can use the same configuration on different systems without clobbering the `custom.el`. Once Emacs fully loads it is available and `(getenv "HOST")` works fine. Is there some reason Emacs behaves this way for this particular variable? **SOLVED** I checked my `.profile` and realized that in this instance the config file which creates the `HOST` variable was not being `source`'d, so I've fixed it in this instance. The problem dates back some years ago when the default Debian environment was not creating a variable I needed so I had to add `export HOST=$(hostname)` to my `.profile` to ensure it would be available to GUI programs.

I'd suspect something trivial like "printer cable not connected" when the printer doesn't work. is HOST exported to child processes in your shell? i.e. is HOST in initial-environment on your system? you can check that by entering the debugger in your init.el add (debug) to your init.el and a `--debug-init` argument on the command line. https://www.gnu.org/software/emacs/manual/html_node/elisp/System-Environment.html https://www.gnu.org/software/emacs/manual/html_node/elisp/Explicit-Debug.html

while this does not answer your initial question about the behavior, I use `(system-name)` and `(system-type)` to do such configuration.

As suggested, by others (system-name) is probably what you are looking for. C-h f system-name RET > > system-name is a built-in function in ‘C source code’. > > (system-name) > > Return the host name of the machine you are running on, as a string. > > Probably introduced at or before Emacs version 19.23.

I think I will switch to `(system-name)` for the future. BTW `system-type` is a variable not a function.

I checked it and realized that in this instance the config file which creates the `HOST` variable was not being `source`'d, so I've fixed it in this instance. The problem dates back some years ago when the default Debian environment was not creating a variable I needed so I had to add `export HOST=$(hostname)` to my `.profile` to ensure it would be available to GUI programs.

see, printer was simply not plugged in ;-) thanks for the update.

I seem to remember `export VAR=VALUE` is a bashism so can’t portably be used in `.profile` which is a POSIX-standardized file. You’re supposed to say `VAR=VALUE` and `export VAR` separately.

Why not use the standard `$HOSTNAME` variable that is set automatically?

`VAR=VAL; export VAR` should be portable

I set it some years ago. I can't remember the reason why but I think back then HOSTNAME was not appropriate or conflicted with something else.