In the documentation for set -e, the Bash manual says that errexit is
suspended in all but the last command of a pipeline:
The shell does not exit if the command that fails is part of
[...] any command in a pipeline but the last
The documentation also of course says that errexit suspension cascades
into compound commands:
If a compound command or shell function executes in a
context where -e is being ignored, none of the commands
executed within the compound command or function body will
be affected by the -e setting, even if -e is set and a
command returns a failure status.
This means the following script should output both "1" and "2":
(false; echo 1) | cat
set -e
(false; echo 2) | cat
However, it only outputs "1". I tested in Bash 4.0 through 5.2.
Is this a bug in the behavior, or is it a bug in the documentation?
