mod_auth_krb and apache 2.2.0

/path_to_apache2.2.0_installation/build/libtool --silent --mode=compile gcc -prefer-pic -DLINUX=2 -D_REENTRANT -D_GNU_SOURCE -D_LARGEFILE64_SOURCE -g -O2 -pthread -I/path_to_apache2.2.0_installation/include -I/path_to_apache2.2.0_installation/include -I/path_to_apache2.2.0_installation/include -I. -Ispnegokrb5 -I/include -c -o src/mod_auth_kerb.lo src/mod_auth_kerb.c && touch src/mod_au
th_kerb.slo
src/mod_auth_kerb.c:155: warning: initialization from incompatible pointer type
src/mod_auth_kerb.c:155: error: syntax error before "kerb_auth_config"
src/mod_auth_kerb.c:155: error: initializer element is not constant
src/mod_auth_kerb.c:155: error: (near initialization for `kerb_auth_cmds[0].cmd_data')
src/mod_auth_kerb.c:155: error: initializer element is not constant
src/mod_auth_kerb.c:155: error: (near initialization for `kerb_auth_cmds[0]')
src/mod_auth_kerb.c:158: warning: initialization from incompatible pointer type
src/mod_auth_kerb.c:158: error: initializer element is not constant
src/mod_auth_kerb.c:158: error: (near initialization for `kerb_auth_cmds[1].func')
src/mod_auth_kerb.c:158: error: syntax error before "kerb_auth_config"
src/mod_auth_kerb.c:158: error: initializer element is not constant
src/mod_auth_kerb.c:158: error: (near initialization for `kerb_auth_cmds[1].cmd_data')
src/mod_auth_kerb.c:158: error: initializer element is not constant
src/mod_auth_kerb.c:158: error: (near initialization for `kerb_auth_cmds[1]')
src/mod_auth_kerb.c:161: error: initializer element is not constant
src/mod_auth_kerb.c:161: error: (near initialization for `kerb_auth_cmds[2].func')
src/mod_auth_kerb.c:161: error: syntax error before "kerb_auth_config"
src/mod_auth_kerb.c:161: error: initializer element is not constant
src/mod_auth_kerb.c:161: error: (near initialization for `kerb_auth_cmds[2].cmd_data')
src/mod_auth_kerb.c:161: error: initializer element is not constant
src/mod_auth_kerb.c:161: error: (near initialization for `kerb_auth_cmds[2]')
src/mod_auth_kerb.c:164: error: initializer element is not constant
src/mod_auth_kerb.c:164: error: (near initialization for `kerb_auth_cmds[3].func')
src/mod_auth_kerb.c:164: error: syntax error before "kerb_auth_config"
src/mod_auth_kerb.c:164: error: initializer element is not constant
src/mod_auth_kerb.c:164: error: (near initialization for `kerb_auth_cmds[3].cmd_data')
src/mod_auth_kerb.c:164: error: initializer element is not constant
src/mod_auth_kerb.c:164: error: (near initialization for `kerb_auth_cmds[3]')
src/mod_auth_kerb.c:167: error: initializer element is not constant
src/mod_auth_kerb.c:167: error: (near initialization for `kerb_auth_cmds[4].func')
src/mod_auth_kerb.c:167: error: syntax error before "kerb_auth_config"
src/mod_auth_kerb.c:167: error: initializer element is not constant
src/mod_auth_kerb.c:167: error: (near initialization for `kerb_auth_cmds[4].cmd_data')
src/mod_auth_kerb.c:167: error: initializer element is not constant
src/mod_auth_kerb.c:167: error: (near initialization for `kerb_auth_cmds[4]')
src/mod_auth_kerb.c:170: error: initializer element is not constant
src/mod_auth_kerb.c:170: error: (near initialization for `kerb_auth_cmds[5].func')
src/mod_auth_kerb.c:170: error: syntax error before "kerb_auth_config"
src/mod_auth_kerb.c:170: error: initializer element is not constant
src/mod_auth_kerb.c:170: error: (near initialization for `kerb_auth_cmds[5].cmd_data')
src/mod_auth_kerb.c:170: error: initializer element is not constant
src/mod_auth_kerb.c:170: error: (near initialization for `kerb_auth_cmds[5]')
src/mod_auth_kerb.c:173: error: initializer element is not constant
src/mod_auth_kerb.c:173: error: (near initialization for `kerb_auth_cmds[6].func')
src/mod_auth_kerb.c:173: error: syntax error before "kerb_auth_config"
src/mod_auth_kerb.c:173: error: initializer element is not constant
src/mod_auth_kerb.c:173: error: (near initialization for `kerb_auth_cmds[6].cmd_data')
src/mod_auth_kerb.c:173: error: initializer element is not constant
src/mod_auth_kerb.c:173: error: (near initialization for `kerb_auth_cmds[6]')
src/mod_auth_kerb.c:177: error: initializer element is not constant
src/mod_auth_kerb.c:177: error: (near initialization for `kerb_auth_cmds[7].func')
src/mod_auth_kerb.c:177: error: syntax error before "kerb_auth_config"
src/mod_auth_kerb.c:177: error: initializer element is not constant
src/mod_auth_kerb.c:177: error: (near initialization for `kerb_auth_cmds[7].cmd_data')
src/mod_auth_kerb.c:177: error: initializer element is not constant
src/mod_auth_kerb.c:177: error: (near initialization for `kerb_auth_cmds[7]')
src/mod_auth_kerb.c:180: error: initializer element is not constant
src/mod_auth_kerb.c:180: error: (near initialization for `kerb_auth_cmds[8].func')
src/mod_auth_kerb.c:180: error: syntax error before "kerb_auth_config"
src/mod_auth_kerb.c:180: error: initializer element is not constant
src/mod_auth_kerb.c:180: error: (near initialization for `kerb_auth_cmds[8].cmd_data')
src/mod_auth_kerb.c:180: error: initializer element is not constant
src/mod_auth_kerb.c:180: error: (near initialization for `kerb_auth_cmds[8]')
src/mod_auth_kerb.c:183: error: initializer element is not constant
src/mod_auth_kerb.c:183: error: (near initialization for `kerb_auth_cmds[9].func')
src/mod_auth_kerb.c:183: error: syntax error before "kerb_auth_config"
src/mod_auth_kerb.c:183: error: initializer element is not constant
src/mod_auth_kerb.c:183: error: (near initialization for `kerb_auth_cmds[9].cmd_data')
src/mod_auth_kerb.c:183: error: initializer element is not constant
src/mod_auth_kerb.c:183: error: (near initialization for `kerb_auth_cmds[9]')
src/mod_auth_kerb.c:195: error: initializer element is not constant
src/mod_auth_kerb.c:195: error: (near initialization for `kerb_auth_cmds[10]')
src/mod_auth_kerb.c: In function `krb5_save_realms':
src/mod_auth_kerb.c:252: warning: assignment makes pointer from integer without a cast
src/mod_auth_kerb.c: In function `create_krb5_ccache':
src/mod_auth_kerb.c:680: warning: assignment makes pointer from integer without a cast
src/mod_auth_kerb.c:711: error: `ap_null_cleanup' undeclared (first use in this function)
src/mod_auth_kerb.c:711: error: (Each undeclared identifier is reported only once
src/mod_auth_kerb.c:711: error: for each function it appears in.)
src/mod_auth_kerb.c: In function `authenticate_user_krb5pwd':
src/mod_auth_kerb.c:869: warning: assignment makes pointer from integer without a cast
src/mod_auth_kerb.c: In function `get_gss_error':
src/mod_auth_kerb.c:905: warning: assignment makes pointer from integer without a cast
src/mod_auth_kerb.c:915: warning: assignment makes pointer from integer without a cast
src/mod_auth_kerb.c:926: warning: assignment makes pointer from integer without a cast
src/mod_auth_kerb.c: In function `authenticate_user_gss':
src/mod_auth_kerb.c:1139: warning: assignment makes pointer from integer without a cast
src/mod_auth_kerb.c:1175: warning: assignment makes pointer from integer without a cast
src/mod_auth_kerb.c:1227: warning: assignment makes pointer from integer without a cast
src/mod_auth_kerb.c: In function `set_kerb_auth_headers':
src/mod_auth_kerb.c:1288: warning: pointer/integer type mismatch in conditional expression
apxs:Error: Command failed with rc=65536
.
gmake: [src/mod_auth_kerb.so] Error 1

It took me a long time once I figured out what the problem was. There are actually two problems with mod_auth_kerb.c file.
1. it was including ap_compat.h, which in turn would include apu_compat.h, which in turn would include apr_compat.h. Both apu_compat.h and apr_compat.h contained all the defines for deprecated functions. That was working ok for Apache versions 2.0.x, but in 2.2.0 ap_compat.h doesn't include any other header files and there are no apu_compat.h and apr_compat.h with a ton of deprecated functions.
2. APR_XtOffsetOf function was renamed into APR_OFFSETOF. Here is a related entry in srclib/apr/CHANGES that's shipped with Apache 2.2.0:

*) Renamed APR_XtOffset -> APR_OFFSET and APR_XtOffsetOf -> APR_OFFSETOF.
[Cliff Woolley]

Solutions to these problems were quite simple after I identified what they were:
1. I extracted an Apache 2.0.55 tarball to get apu_compat.h and apr_compat.h and dumped them into src directory where mod_auth_kerb.c file was. I added the following two lines to mod_auth_kerb.c file on line 60:
#include "apr_compat.h"
#include "apu_compat.h"

2. in src/mod_auth_kerb.c I replaced APR_XtOffsetOf with APR_OFFSETOF.

I re-ran make and it all compiled successfully.

Hopefully mod_auth_kerb developers will have a new version ready soon. Although, since rc6 was released about year and a half ago(August 9, 2004), I wouldn't expect them to.