Guide to Installing and Using CGDB for Debugging MySQL on CentOS

CGDB (Curses‑based GDB) is a text‑mode front‑end for GDB that provides a richer interface using the curses library. It requires a compatible GDB version (≥7.12) and is often used on CentOS 7.5.

Version selection : The article recommends installing GDB 9.2 because the default CentOS 7.5 GDB (7.6.1) is too old for CGDB and because GDB ≥9.0 is needed to debug OBServer.

Installing CGDB :

yum -y install automake flex texinfo ncurses-devel readline-devel gcc-c++
git clone https://github.com/cgdb/cgdb.git
cd cgdb
./autogen.sh
./configure --prefix=/usr/local
make && make install

If error: ‘for’ loop initial declarations are only allowed in C99 mode occurs, re‑run configure with CFLAGS="-std=c99" .

Installing GDB (example for version 9.2):

yum -y install gcc gcc-c++ texinfo
wget ftp://ftp.gnu.org/gnu/gdb/gdb-9.2.tar.gz
tar zxf gdb-9.2.tar.gz -C /tmp
cd /tmp/gdb-9.2
mkdir build && cd build
/tmp/gdb-9.2/configure
make && make install

After installation, verify the GDB version and launch cgdb to start debugging.

Help commands : In GDB type help ; in CGDB type ESC :help to list commands.

Debugging examples demonstrate attaching to a MySQL mysqld process, inspecting threads, stepping through code, analyzing core dumps, using cgdb -p , and modifying MySQL runtime variables such as max_connections . The article also warns against using CGDB in production environments.

Summary : CGDB offers a convenient way to visualize GDB debugging sessions, analyze core dumps, and adjust MySQL internals, making it valuable for learning, troubleshooting, and occasional emergency fixes.