are you kidding me?

[root@srv-rhsoft:~]$ /usr/bin/mpd --no-daemon --stderr /usr/bin/mpd: symbol lookup error: /lib64/libid3tag.so.0: undefined symbol: id3_compat_fixup

2018-03-30T10:57:03Z INFO Upgraded: kid3-common-3.6.0-1.fc27.x86_64 2018-03-30T10:57:03Z INFO Upgraded: kid3-3.6.0-1.fc27.x86_64 2018-03-30T10:57:05Z INFO Upgraded: libid3tag-0.15.1b-25.fc27.x86_64

i even re-compiled "mpd", stil don't work [root@srv-rhsoft:~]$ /usr/bin/mpd --no-daemon --stderr /usr/bin/mpd: symbol lookup error: /lib64/libid3tag.so.0: undefined symbol: id3_compat_fixup

It looks to me like gperf is not a build requirement and with the patch to compat.gperf, the Makefile tries to use it to rebuild compat.c. This fails and creates an empty compat.c. Here's a snip from the build.log:

config.status: executing depfiles commands
+ make -j48 'CFLAGS=-O2 -g -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -m64 -mtune=generic -fasynchronous-unwind-tables'
cd . &&  \
gperf -tCcTonD -K id -N id3_compat_lookup -s -3 -k '*'  \
    compat.gperf |  \
sed -e 's/\(struct id3_compat\);/\1/' |  \
sed -e '/\$''Id: /s/\$//g' >compat.c
/bin/sh: line 1: gperf: command not found
make  all-recursive

Unfortuantely, adding gperf causes the build to fail:

compat.gperf:116:1: error: conflicting types for 'id3_compat_lookup'
 TSIZ, OBSOLETE  /* Size [obsolete] */
 ^~~~~~~~~~~~~~~~~
In file included from compat.gperf:37:0:
compat.h:36:26: note: previous declaration of 'id3_compat_lookup' was here
 struct id3_compat const *id3_compat_lookup(register char const *,
                          ^~~~~~~~~~~~~~~~~

I haven't looked any further at how to resolve this yet, but thought I'd post what I've found in case someone else has time to work on this.