error while loading shared libraries: libpq.so.5: cannot open shared object file: No such file or directory

This error occurs when the system is unable to locate the required shared library file "libpq.so.5". This file is part of the PostgreSQL database client library. To resolve this issue, you can follow the steps below:

1. Check if PostgreSQL is installed on your system. If not, you need to install it.
- On Ubuntu, you can use the following command to install PostgreSQL:

     sudo apt-get install postgresql

2. Once PostgreSQL is installed, you might need to reinstall the PostgreSQL client package to ensure all the necessary files are present:
- On Ubuntu, you can use the following command to reinstall the client package:

     sudo apt-get install --reinstall libpq5

3. If the issue persists, it's possible that the library file is located in a non-standard path. In that case, you can try adding the path to the `LD_LIBRARY_PATH` environment variable:

   export LD_LIBRARY_PATH=/path/to/pg_lib:$LD_LIBRARY_PATH

Replace "/path/to/pg_lib" with the actual path where the "libpq.so.5" file is located.

4. Finally, if none of the above steps solve the problem, you may need to manually create a symbolic link to the library file in one of the standard library directories:

   sudo ln -s /path/to/libpq.so.5 /usr/lib/libpq.so.5

Replace "/path/to/libpq.so.5" with the actual path where the library file is located.

Please note that these steps may vary depending on your operating system and distribution. Make sure to adapt them accordingly.