Re: [Module-build-general] [BUG] non-numeric $VERSION comparison error

[Steve P. <sp...@qu...>]

On Tuesday, July 29, 2003, at 08:48  pm, Ken Williams wrote:

> On Tuesday, July 29, 2003, at 06:00  AM, Steve Purkis wrote:
>
>> [snip - version bug]
>
> Good catch.  The version comparison stuff probably needs some work, 
> and I'm not sure I'm completely up-to-date on the Totally Correct way 
> to compare version numbers/strings.  Do you know much about this?

I'm not too up-to-date on them either, I'm afraid.  But I reckon John 
Peacock's version.pm would be a good place to start.

I suppose it's worth asking this: why not use version objects?


> (By the way, you probably should use 'build_requires' rather than 
> 'requires' for the Module::Build dependency.  I'm sure that has the 
> same bug, though.)

Yup, that was for sake of argument.  Still happens when you use 
'build_requires'..

Further investigation leads me to an eval() in 
M::B::Base->check_installed_status:

	...
	unless (eval "\$status{have} $op \$version") {
		...

Which works for most things.  I think it break because of how perl does 
SV -> NV conversions [1]:

	'0.03_01' > '0.03' == false

Because '0.03_01' is converted to 0.03.  But:

	0.03_01 > 0.03 == true

Because 0.03_01 is really 0.0301.

-Steve

[1] - I don't remember if this has changed over the last versions of 
perl...