bash: warning: shell level (1000) too high, resetting to 1

Question

I just tried to run this command:

/etc/ssl/acme/acme.sh --log /var/log/p3x/acme/acme.sh.log --home /etc/ssl/acme --force --issue -d patrikx3.tk -w /var/www/acme-challenge

I got this error:

bash: warning: shell level (1000) too high, resetting to 1

What is this error?

Answer 1

Shell Level identify the level of sub-shell in a nested shell

Bash man - Shell Level SHLVL

SHLVL - Incremented by one each time a new instance of Bash is started.

• This is intended to be a count of how deeply your Bash shells are nested.

As you can see here

When bash execute itself the bash shell level is higher in 1

The following recursive call to bash:

$ echo "bash haha" > haha
$ bash haha

Got this message periodically:

bash: warning: shell level (1000) too high, resetting to 1

The meaning of the error above is that bash called itself 1000 times

Another example how $SHLVL variable tracks your shell nesting level:

$ echo $SHLVL
1
$ bash
$ echo $SHLVL
2
$ exit
$ echo $SHLVL
1