bash-it emits bashdb error without bashdb installed

[ravenhall]

Just pulled from master and now I'm seeing this error when launching bash:

bash: /usr/share/bashdb/bashdb-main.inc: No such file or directory
bash: warning: cannot start debugger; debugging mode disabled

I'm on Red Hat Enterprise Linux Server release 7.3 (Maipo).
bashrc.txt
bash_profile.txt
bash-itplugins.txt

[nwinkler]

It looks like this is related to this line: https://github.com/Bash-it/bash-it/blob/master/lib/preexec.bash#L122

shopt -s extdebug > /dev/null 2>&1

References:

• https://gitlab.com/gnachman/iterm2/issues/4160
• preexec doesn't work for function declarations rcaloras/bash-preexec#6
• https://serverfault.com/questions/745837/bash-to-start-missing-debugger-after-update-to-4-2

Skimming through these, it looks like this error is caused by the above line on specific versions of Bash. The issues describe it in the context of iTerm2, which uses a similar preexec integration script.

Not sure how to fix it - the above links contain a couple of potential workarounds, but I don't have a system to test this...

[ravenhall]

I can test if a solution can be sussed out from those threads. The only clear workaround I see is checking if bashdb is installed in the preexec_install() function before setting the DEBUG trap on L130.

Installing a VM with CentOS 7.2 and then bash-it exhibits the same behavior.

[ravenhall]

It looks as though another potential could be that a failed check for bashdb could run shopt -u extdebug to disable the external debugger.

[ravenhall]

There is an interesting article on Season of Code with a description of how the DEBUG trap and PROMPT_COMMAND can be employed to emulate zsh's preexec hook. The page notes that a PS0 variable patch that simplified this was accepted into Bash 4.4.

How should bash-it handle this?

1. Check for Bash 4.4 and use a PS0 implementation only
2. Check for Bash 4.4 and use PS0 implementation with fallback to DEBUG/PROMPT_COMMAND
3. DEBUG/PROMPT_COMMAND only (current solution)

[ravenhall]

Additionally, I am not sure that the current implementation is working as expected. It looks as though the preexec_invoke_exec hook is being executed three times after the command is invoked due to the pipelined command prompt_command;__vte_prompt_command;preexec_invoke_cmd which is in RedHat's /etc/bashrc.

preexec_invoke_exec.txt

[nshiell]

I have this issue on KDE Neon
Linux saturn 4.15.0-76-generic #86-Ubuntu SMP Fri Jan 17 17:24:28 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

What's the best way to remove this?

[NoahGorny]

hey @nshiell
are you still experiencing this bug?

[hv15]

Hi, I get this on CentOS 7 using Bash 4.2.46(2)-release using the latest version of bash-it.

[NoahGorny]

seems like the solution is to install bashdb, and the error should go away.

Feel free to reopen if it does not help

[palladius]

Same here, on Mac:

./blah.sh: /opt/homebrew/Cellar/bash/5.2.15/share/bashdb/bashdb-main.inc: No such file or directory

I believe the issue was:

#!/bin/bash

set -euo pipefail

I changed it to

#!/bin/bash

and the shebang worked.