CMake errors while building

[GaryBlackbourne]

I am currently building version 22.6.1 on Fedora 38, and encountered an error. While running cmake :

CMake Error at CMakeLists.txt:116 (string):
  string sub-command REGEX, mode MATCH needs at least 5 arguments total to
  command.


CMake Error at CMakeLists.txt:118 (message):
  Error matching PostgreSQL version.

I have spent some time debugging and found that there are two main problems.

Delusive error message with regex

In CMakeLists.txt:116 the variable PostgreSQL_VERSION_STRING is empty, which creates the first error, because there is nothing there. This can be bypassed by quoting the variable to "${PostgreSQL_VERSION_STRING}" which removes the first, unnecessary and delusive error message.

Not found version to an installed package

The second error is caused by the version query algorithm in cmake/FindPostgreSQL.cmake. To my current understanding, this script iterates through the include paths, and find all files named: pg_config*.h. Then iterates through these files and tries to find a specific C macro called #define PG_VERSION_NUM <some-version-info>. I have tweaked my way around this problem, by adding the next line to CMakeLists.txt before the find_package call:

set(PostgreSQL_INCLUDE_DIR "/usr/include") 

Apparently CMake on this distribution fails to find the appropriate include directory, and after this modification the package seems to compile without further trouble .

I am not sure if there is any other, more elegant way of getting rid of these errors, as I am far from an expert in cmake, but this may worth a fix.

[hasnimehdi91]

Faced the same on Rocky Linux 8 and AlmaLinux 8