Ubuntu – Why doesn’t “whereis” locate a file

I think you have only to activate the bash globstar option, because it is not active by default in Ubuntu, as explained in the following.

The expression /path/to/music/directory/{**/,}* contain two expansion constructs: has a brace expansion and next a pathname expansion.

Brace expansion

Brace expansion is best explained with an example:

$ printf '%s\n' before-{a,bb,1,22}-after
before-a-after
before-bb-after
before-1-after
before-22-after

(I've used, here and in the following, the command printf '%s\n' item1 item2 etc.. that is like echo but prints each element on a new line)

You see that each comma separated element in braces results in an expanded element.

The original example, containing in braces the elements **/ and an empty element, expands to

$ printf '%s\n' /path/to/music/directory/{**/,}*
/path/to/music/directory/**/*
/path/to/music/directory/*

Globstar

Turn now to the bash glob **, that is mentioned two times in the bash manual page, both in relation to the shell option globstar, and the meaning is as follow:

the pattern ** used in a pathname expansion context will match a files and zero or more directories and subdirectories.

This shell option is not active by default in Ubuntu:

$ shopt globstar
globstar        off

You can activate it with

shopt -s globstar

(use shopt -u globstar to deactivate it).

If we have the following directory structure:

$ find first/ | sort
first/
first/aaa
first/second
first/second/bbb01
first/second/bbb02
first/second/third
first/second/third/ccc1
first/second/third/ccc2
first/second/third/ccc3

we could have the following expansions:

$ printf '%s\n' first/**/a*
first/aaa

$ printf '%s\n' first/**/b*
first/second/bbb01
first/second/bbb02

$ printf '%s\n' first/**/c*
first/second/third/ccc1
first/second/third/ccc2
first/second/third/ccc3

so you can see that ** is able to expand to more than a pathname element.

When you do ls * the * is being expanded before it is passed to ls. That is to say if we have three files (a, b and c) in a directory ls * is actually running ls a b c.

When Bash can't expand, it passes through the raw string¹. That's why you see the wildcards in the error, along with a not found message. ls tried to show the listing for a file literally called *.bash*.

So why didn't that expand? Well by default globbing (what this wildcard expansion is called) won't return hidden files. You can change this with shopt -s dotglob (that won't persist unless you stick it in your .bashrc — it might be disabled by default for a good reason so be careful with it), here's a quick demo:

$ ls  *.bash*
ls: cannot access *.bash*: No such file or directory
$ shopt -s dotglob
$ ls  *.bash*
.bash_aliases  .bash_history  .bash_logout  .bashrc  .bashrc.save

The exception to this is —as you've already shown— when you've already explicitly stated the files will be hidden with a pattern like .bash*. It simply overrides the default dotglob setting:

$ shopt -u dotglob  # unset dotglob
$ ls .bash*
.bash_aliases  .bash_history  .bash_logout  .bashrc  .bashrc.save

Anyway besides that quirk, I hope this helps you understand what's going on under the surface.

There are other shopt flags that alter how globbing works: extglob, failglob, globstar, nocaseglob and nullglob. They and a raft of other shopt flags are documented as part of the Bash manual.

Similarly, the page on Pattern Matching should make for some good reading.

¹ Unless failglob or nullglob are set.