Here is the error we're seeing when trying to compile 5.2.5. No problem with 5.2.4.

if g++45 -DMYSQL_SERVER -DDEFAULT_MYSQL_HOME='"/usr/local"' -DMYSQL_DATADIR='"/usr/local/var"' -DSHAREDIR='"/usr/local/share/mysql"' -DPLUGINDIR='"/usr/local/lib/mysql/plugin"' -DHAVE_EVENT_SCHEDULER -DHAVE_CONFIG_H -I. -I. -I../include -I../include -I../include -I../regex -I. -O2 -pipe -mfpmath=sse -ftracer -ffast-math -fexcess-precision=fast -funroll-loops -O3 -floop-interchange -floop-strip-mine -floop-block -march=native -fno-strict-aliasing -fno-implicit-templates -fno-exceptions -fno-rtti -DMYSQLD_NET_RETRY_COUNT=1000000 -MT sql_select.o -MD -MP -MF ".deps/sql_select.Tpo" -c -o sql_select.o sql_select.cc; then mv -f ".deps/sql_select.Tpo" ".deps/sql_select.Po"; else rm -f ".deps/sql_select.Tpo"; exit 1; fi
mysqld.cc: In function 'void init_signals()':
mysqld.cc:2764:7: error: 'opt_stack_trace' was not declared in this scope
mysqld.cc: In function 'int get_options(int*, char**)':
mysqld.cc:9246:5: error: 'opt_stack_trace' was not declared in this scope

• • • Error code 1
      1 error
    • Error code 1
      1 error
    • Error code 2
      1 error
    • Error code 1
      1 error

It failed even with these basic CFLAGS:
-O2 -pipe -mfpmath=sse -ftracer -fexcess-precision=fast -funroll-loops -march=native -fno-strict-aliasing