Current in bash 5.0 and earlier, the value of BASH_REMATCH might chanted inside a debug hook.
Since BASH_REMATCH is read-only, resetting the value on hook return to the debugged program is a bit tricky and fragile... There are way to change a bash readonly variable but that involve using either gdb or having a custom plugin. See https://stackoverflow.com/questions/17397069/unset-readonly-variable-in-bash The way that bashdb currently resets BASH_REMATCH is to reissue the command that caused the value to get initially set. That is fragile since this set on exit between stepping from the time BASH_REMATCH was set until the time it is last used. In between variables used in the regular expression may have changed. Here is the code bashdb currently uses https://sourceforge.net/p/bashdb/code/ci/bash-5.0/tree/lib/hook.sh#l105 for saving the value if (( ${#BASH_REMATCH[@]} > 0 )) && [[ "${_Dbg_bash_rematch[@]}" != "${BASH_REMATCH[@]}" ]]; then # Save a copy of the command string to be able to run to restore read-only # variable BASH_REMATCH _Dbg_bash_rematch=${BASH_REMATCH[@]} _Dbg_last_rematch_args=( "$@" ) _Dbg_last_rematch_command=$_Dbg_bash_command unset _Dbg_last_rematch_args[0] elif ((!${#BASH_REMATCH[@]} && ${#_Dbg_bash_rematch[@]})); then _Dbg_bash_rematch=() _Dbg_last_rematch_command='' fi Restoring it is just as tricky. As I hope you see all of this is a bit fragile.
