bash.asc | Warn about the version of the source code

Author: patricekrakow

book/A-git-in-other-environments/sections/bash.asc

@@ -5,6 +5,9 @@ If you're a Bash user, you can tap into some of your shell's features to make yo
 Git actually ships with plugins for several shells, but it's not turned on by default.
 
 First, you need to get a copy of the `contrib/completion/git-completion.bash` file out of the Git source code.
+Make sure to get it from the version of the source code that corresponds to the version of Git your are using.
+You can find the version of Git you are using with the command `git version`.
+You can then select the corresponding tag on the Git source code, using `git checkout tags/vX.Y.Z`, where `vX.Y.Z` corresponds to the version of Git you are using.
 Copy it somewhere handy, like your home directory, and add this to your `.bashrc`:
 
 [source,console]