[Rubygems-developers] 'require_gem' with ambiguous names...

[Jamis Buck]

Gavin Sinclair wrote:
> On Monday, September 13, 2004, 2:34:38 PM, Jamis wrote:
> 
> 
>>Disclaimer: I'm still using 0.7, so I don't know if this is fixed in 0.8.
> 
> 
>>I've got four gems: copland, copland-lib, copland-remote, and 
>>copland-webrick. When I do a "require_gem 'copland'", all four of those
>>match, and because 'copland-webrick' is the last one in the list, it is
>>the one that gets required. Fortunately, copland-webrick has a 
>>dependency on copland, so all works out okay, but it wasn't quite what I
>>expected.
> 
> 
>>Is this already fixed?
> 
> 
> Are you saying that require_gem is inexact in its behaviour?  If so,
> wow...  dunno if it's fixed.
> 
> Where are these four gems you've got?  Are they planned releases?
> 
> Gavin

Already released, in fact. And in the gem repository.

I discovered the problem like this:

1) Install copland and copland-webrick gems.

2) Start irb.

3) Do 'require "copland"' (or 'require_gem "copland"', either works)

4) Inspect the value of Copland::LIBRARIES.keys

The Copland::LIBRARIES variable is a hash of search paths that Copland 
can use for finding installed packages. Given the above use case, it 
_should_ contain only a single key, "copland". However, with 0.7, I get 
two keys, "copland" and "copland/webrick".

I put some debugging in my copy of rubygems.rb, in the "require_gem" 
method, and it looks like all of the copland* gems are matching when I 
do a 'require_gem "copland"' (without an explicit version). Then, it 
grabs the last one in the list, which is theoretically the one with the 
highest version. (Not true in this case, though -- copland is 0.7.0, 
copland-webrick is 0.1.0 -- it looks more like the gems are sorted 
alphabetically). Then, it returns that gem, which is in this case 
'copland-webrick'.

In this case, copland-webrick has a dependency on copland (>= 0.7.0), so 
the correct copland gem gets loaded eventually anyway. But it took me a 
while to understand why copland-webrick was being loaded everytime I 
loaded copland.

Hope that is clear enough for someone to see if it is happening in 0.8...

- Jamis

-- 
Jamis Buck
jgb3 at email.byu.edu
http://www.jamisbuck.org/jamis

"I use octal until I get to 8, and then I switch to decimal."