Bash subshell in Terminal has Mac OS's session save enabled At some point, Terminal started saving sessions. It's controlled with /etc/bashrc_Apple_Terminal. For some reason, my subshells are also using this feature:

echo $(cd &amp;&amp; pwd)
/Users/ehrmann Saving session... ...saving history...truncating history files... ...completed.


As a workaround, I can do

echo $(SHELL_SESSION_FILE= &amp;&amp; cd &amp;&amp; pwd)


Luckily, it works across platforms, but it's kinda silly.

Did I accidentally do something that turned this on? This can't be the intended default behavior&mdash;it breaks all sorts of things.
I’m not certain when this became the default, but I agree, it’s an annoying default; it was added in one of the last few major releases. I came across this question because I was searching for how to best disable this, and I think you may have provided the solution yourself:

In /etc/bashrc_Apple_Terminal, there is great amount of documentation about how the functionality in the file is implemented.

The final comment is the kicker:

# The save/restore mechanism is disabled if the following file exists:
#
#   ~/.bash_sessions_disable


I tested this on my machine and it works, no more session saving.