BASH /usr/bin/adb No Such File or Directory

Using Xubuntu (Ubuntu) 16.04.3 I encountered a strange problem. I’d removed the Android debugging tools using the command:

my@myhost:~$ sudo apt-get remove android-tools-adb

I did this because I installed the latest platform tools manually from Google directly.

So next time I went to run adb I didn’t expect to see the following:

my@myhost:~$ adb
bash: /usr/bin/adb: No such file or directory

The answer was found in this forum post. I did not realise this but BASH actually caches executables found in the $PATH to avoid having to perform future searches.

The type command can reveal whether an executable has been stored in the cache (or “hashed”):

my@myhost:~$ type adb
adb is hashed (/usr/bin/adb)

To clear the entire cache the following command can be run:

my@myhost:~$ hash -r

.. but it might be preferable to only clear that command that has been removed from the cache:

my@myhost:~$ hash -d adb