I see, in my mind it remained an irrefutable fact that the DEBUG trap is executed after a simple command. Most probably because it is written like so in a Bash Beginners Guide https://tldp.org/LDP/Bash-Beginners-Guide/html/sect_12_02.html

https://ss64.com/bash/trap.html does explain it reliably.

It is a bit counterintuitive, but a workaround with a FIFO is possible though. It is because I need to highlight traced commands with certain status codes. So I have to print $BASH_COMMAND after it is executed.

I am writing a debugging helper which echoes traced functions and related commands during script execution.

Now

$ trap 'status=$?; echo $LINENO $BASH_COMMAND [$status]' DEBUG;

echoes the traced command, but the status returns from the previous command. So as a result the status always lacks behind. Thats because $ 'status=$?'; captures the previous command's status, which is not $BASH_COMMAND itself.

$ false # gives two lines
224 false [0]
$ true # shows command but previous status
225 true [1]

Shouldn't the output look like the following?

$ false
224 false [1]
$ true
225 true [0]


Workarounds are possible but disproportionate complicated IMHO.