PolyBoRi fails to build on cygwin

[mwhansen]

It fails with

  /home/mhansen/sage-4.2/spkg/build/gd-2.0.35.p2/src/gd_png.c:70: undefined reference to `_png_get_error_ptr'
  /home/mhansen/sage-4.2/local/lib/libgd.a(gd_png.o): In function `gdPngReadData':
  /home/mhansen/sage-4.2/spkg/build/gd-2.0.35.p2/src/gd_png.c:85: undefined reference to `_png_get_io_ptr'
  /home/mhansen/sage-4.2/spkg/build/gd-2.0.35.p2/src/gd_png.c:87: undefined reference to `_png_error'
  /home/mhansen/sage-4.2/local/lib/libgd.a(gd_png.o): In function `gdPngWriteData':
  /home/mhansen/sage-4.2/spkg/build/gd-2.0.35.p2/src/gd_png.c:94: undefined reference to `_png_get_io_ptr'
  /home/mhansen/sage-4.2/local/lib/libgd.a(gd_png.o): In function `gdImageCreateFromPngCtx':
  /home/mhansen/sage-4.2/spkg/build/gd-2.0.35.p2/src/gd_png.c:152: undefined reference to `_png_check_sig'

This can be fixed by adding png12 and z to the list of libraries needed when gd is present.

I'll post an spkg shortly.

CC: @williamstein

Component: porting: Cygwin

Author: Mike Hansen

Reviewer: William Stein

Merged: sage-4.4.3.alpha1

Issue created by migration from https://trac.sagemath.org/ticket/7337

[mwhansen]

comment:1

This no longer fails with Cygwin 1.7.

[mwhansen]

comment:2

So, it turns out this is still an issue.

[mwhansen]

comment:3

There's an spkg which should fix this at http://sage.math.washington.edu/home/mhansen/polybori-0.6.4.p1.spkg

[mwhansen]

Author: Mike Hansen

[williamstein]

comment:4

looks good

[williamstein]

Reviewer: wstein

[williamstein]

Merged: 4.4.3.alpha1