Blacklisting compiler versions or build numbers

[Rainer Müller]

On 2012-12-09 05:05, Ryan Schmidt wrote:
> If clang >= 421 fails to build the port, then the blacklist entry
> should not be removed unless the source gets modified to work around
> the clang bug.

Agreed, but how do you know it's really any later version after 421 when
adding the blacklist entry? It might just be a bug in this specific release.

> If a later version of clang e.g. 555 eventually does compile the port
> correctly, then amend the blacklist with that information.
> 
> compiler.blacklist-append {clang >= 421 < 555}

The problem here is to detect which version of clang is able to compile
this port again. Will the maintainer remember to remove the blacklist
entry and try again every time a new Xcode release becomes available?

So it might happen that we discover later that build 777 works again,
although we could already have lifted the blacklist as of build 555 just
nobody tried this build.

As I understand it, the reason for the introduction of the port group
was to avoid unnecessary blacklisting of compilers, but that will happen
again when the blacklist entry matches too many releases of the compiler.

Rainer