libgd compiled with vpx support can has matrix_mod2_dense to fail to load, lah

[embray]

There is a problem in the Cygwin package repository where there is a version of the libvpx package that is compiled against a newer version of the Cygwin DLL than is properly set in its dependencies.

The result is that if the libvpx-devel system package is installed, when compiling libgd it will enable vpx support but that doesn't actually work, and actually causes any DLLs linked to libgd (i.e. sage.matrix.matrix_mod2_dense) to fail to load.

Component: porting: Cygwin

Author: Erik Bray

Branch/Commit: cec95ac

Reviewer: Dima Pasechnik

Issue created by migration from https://trac.sagemath.org/ticket/27970

[embray]

New commits:

cec95ac

Trac #27970: Disable vpx support when building libgd for Cygwin

[embray]

Branch: u/embray/cygwin/build/issue-27901

[embray]

Commit: cec95ac

[dimpase]

comment:2

LGTM

[dimpase]

Reviewer: Dima Pasechnik

[embray]

comment:3

Thanks!

[embray]

comment:5

lah?

[dimpase]

comment:6

Singlish, lah!

[vbraun]

Changed branch from u/embray/cygwin/build/issue-27901 to cec95ac

[embray]

comment:8

Not in Sage 8.8. Let's please to try keep tickets' milestones related to the release in which we actually intend to include them, and in particular the release in which they were actually included, especially when closing tickets.