mysql-native and _D5mysql12__ModuleInfoZ

[Steven Schveighoffer]

On 5/21/21 11:47 AM, Guillaume wrote:
> Hi,
> 
> I have a vibed project that uses mysql-native version 3.0.1. It compiles 
> fine with dmd 2.094.2 but not with any version after that, even with the 
> latest beta. At link I get the following error:
> 
> undefined reference to `_D5mysql12__ModuleInfoZ'
> 
> It looks to be related to this https://github.com/dlang/dub/pull/2039 
> and to this https://github.com/mysql-d/mysql-native/issues/224
> 
> Are there any ways to fix this or if I'm stuck with 2.094.2 until 
> there's a fix somewhere?

Yes, that's exactly the problem. My hope was that the DUB PR would be 
reverted, but it hasn't.

However, as others have pointed out, you can downgrade dub to that 
version and it will work. Note that you still have to re-download 
mysql-native from the registry after downgrading because the modified 
dub.json file is cached the first time it's downloaded by the new dub.

This change to DUB has really been a terrible idea. It is not only 
significantly changing the semantics of existing recipes, but it 
rewrites the recipe file on the fly for caching! Code that depends on 
the feature will not work with prior versions of dub, and some projects 
(such as mysql-native) will not work with newer versions of dub.

IMO, this should be reverted, and the feature enabled with a new 
directive, instead of changing the behavior of an existing directive. To 
that end: https://github.com/dlang/dub/pull/2134

I can potentially modify mysql-native to not use this directive, but 
this means mysql-native prior to this version is NOT USABLE with newer 
versions of the compiler. And to require an upgrade (possibly a major 
upgrade) just to use a new compiler because the build tool changed is 
unacceptable.

Another example of a needless breaking change in D...

-Steve