The man pages can't be found:
buczek@geniux:~$ perf help stat
No manual entry for perf-stat
The reason is, that the files get installed into "/" instread if "/usr",
because upper case PREFIX seems to be ignored by the build system. So
the man-pages where installed on the distmaster into /share/man, which
is invalid and is not disted to other nodes.
[BEE] make -j 12 install PREFIX=/usr EPREFIX=/usr BINDIR=/usr/bin SBINDIR=/usr/sbin LIBEXECDIR=/usr/libexec SYSCONFDIR=/etc SHAREDSTATEDIR=/var LOCALSTATEDIR=/var LIBDIR=/usr/lib
INCLUDEDIR=/usr/include DATAROOTDIR=/usr/share DATADIR=/usr/share INFODIR=/usr/share/info LOCALEDIR=/usr/share/locale MANDIR=/usr/share/man DOCDIR=/usr/share/doc/perf DESTDIR=/scr
atch/local/bee-buczek/perf/perf-5.6.14-0/image
[...]
-rwxr-xr-x root/root 1034256 2020-05-20 09:38 /lib/libperf-gtk.so
drwxr-xr-x root/root 0 2020-05-20 09:38 /lib/traceevent/
drwxr-xr-x root/root 0 2020-05-20 09:38 /lib/traceevent/plugins/
-rwxr-xr-x root/root 18032 2020-05-20 09:38 /lib/traceevent/plugins/plugin_jbd2.so
-rwxr-xr-x root/root 20328 2020-05-20 09:38 /lib/traceevent/plugins/plugin_hrtimer.so
[...]
Supply lower-cased prefixed argument as well, which seems to be honored:
[BEE] make -j 12 install PREFIX=/usr EPREFIX=/usr BINDIR=/usr/bin SBINDIR=/usr/sbin LIBEXECDIR=/usr/libexec SYSCONFDIR=/etc SHAREDSTATEDIR=/var LOCALSTATEDIR=/var LIBDIR=/usr/lib
INCLUDEDIR=/usr/include DATAROOTDIR=/usr/share DATADIR=/usr/share INFODIR=/usr/share/info LOCALEDIR=/usr/share/locale MANDIR=/usr/share/man DOCDIR=/usr/share/doc/perf DESTDIR=/scr
atch/local/bee-buczek/perf/perf-5.6.14-0/image prefix=/usr
[...]
drwxr-xr-x root/root 0 2020-05-20 09:58 /usr/lib/traceevent/
drwxr-xr-x root/root 0 2020-05-20 09:58 /usr/lib/traceevent/plugins/
-rwxr-xr-x root/root 18032 2020-05-20 09:58 /usr/lib/traceevent/plugins/plugin_jbd2.so
-rwxr-xr-x root/root 20328 2020-05-20 09:58 /usr/lib/traceevent/plugins/plugin_hrtimer.so
[...]
Because PREFIX is now honored, remove $D$PREFIX/lib/perf/examples
instead of $D/lib/perf/examples.