Trouble building 21.4.22

[Julian Bradfield]

On 2012-02-11, Alan Mackenzie <acm at muc.de> wrote:
> When I try to build XEmacs-21.4.22 on a fully normal Gnu/Linux system, I
> get the following errors:
>
> gcc -c -g -O3 -Wall -Wno-switch -Winline -Wmissing-prototypes -Wsign-compare -fno-strict-aliasing -Wshadow  -Demacs -I. -DHAVE_CONFIG_H glyphs-eimage.c
> glyphs-eimage.c: In function 'png_instantiate':
> glyphs-eimage.c:940:22: error: dereferencing pointer to incomplete type

> Has anybody else seen this, or can anybody offer me any suggestions?

Suggestion: google the error message and png, and read the first
few hits.
XEmacs is using no longer supported direct access to png structures.
Downgrade your png, or change the code to use the advertised methods.