Postgres example errors out during compile on Windows

[kpeters58]

Windows 10

Trying to compile the Postgres example from Github:

D:\projects\v\postgres>\vlang\v.exe main.v
C:\Users\kpeters\AppData\Local\Temp\v\main.tmp.c:221:10: fatal error: libpq-fe.h: No such file or directory
 #include <libpq-fe.h>
          ^~~~~~~~~~~~
compilation terminated.
V error: C error. This should never happen.
Please create a GitHub issue: https://github.com/vlang/v/issues/new/choose

[Ivo-Balbaert]

I encountered the same error on Windows 10 with Postgres freshly installed and its installation directory E:\PostgreSQL\bin and E:\PostgreSQL\include (which contains libpq-fe.h !) in the PATH variable.
I also tried the following (which helped in other cases) but the error remains:

Copy libpq-fe.h from E:\PostgreSQL\include to C:\Users\CVO\AppData\Local\Temp\v
copy libpq-fe.h near customer.v: idem
copy libpq-fe.h to C:\mingw-w64\bin\mingw64\x86_64-w64-mingw32\lib: idem
copy libpq.dll near customer.v and in local\temp\v : idem

It is clearly a PostgreSQL on Windows problem, doesn't happen on Linux.

[enghitalo]

So try installing libpq-dev or its equivalent for your OS:

For Ubuntu/Debian systems: sudo apt-get install libpq-dev
On Red Hat Linux (RHEL) systems: yum install postgresql-devel
For Mac Homebrew: brew install postgresql
For Mac MacPorts PostgreSQL: gem install pg -- --with-pg-config=/opt/local/lib/postgresql[version number]/bin/pg_config
For OpenSuse: zypper in postgresql-devel
For ArchLinux: pacman -S postgresql-libs

[ArtemkaKun]

@walkingdevel Do you have a possibility to test this and eventually close this?

[ghost]

@ArtemkaKun, for now, I would keep it open. I will have a Windows device within a month, and then I will be able to check everything.

[omerrob]

This also happens in macos with macports. I ran the required gem install pg -- --with-pg-config=/opt/local/lib/postgresql[version number]/bin/pg_config command and I can find libpq-fe.h manually if I

$ locate libpq-fe
/opt/local/include/postgresql13/libpq-fe.h

[omerrob]

OK. So apparently, because https://github.com/vlang/v/blob/master/vlib/db/pg/pg.v will look at $pkgconfig('libpq') to find the correct flags or it will assume postgresql11 is used (macports uses /opt/local/):

$if $pkgconfig('libpq') {
	#pkgconfig --cflags --libs libpq
} $else {
	#flag -lpq
	#flag linux -I/usr/include/postgresql

	#flag darwin -I/opt/local/include/postgresql11
	#flag darwin -L/opt/local/lib/postgresql11

	#flag darwin -I/usr/local/opt/libpq/include
	#flag darwin -L/usr/local/opt/libpq/lib

	#flag darwin -I/opt/homebrew/include
	#flag darwin -L/opt/homebrew/lib

	#flag darwin -I/opt/homebrew/opt/libpq/include
	#flag darwin -L/opt/homebrew/opt/libpq/lib

	#flag windows -I @VEXEROOT/thirdparty/pg/include
	#flag windows -L @VEXEROOT/thirdparty/pg/win64
}

It's possible that because I'm using fish shell, macports didn't set PKG_CONFIG_PATH correctly. Once I ran

set -Ux PKG_CONFIG_PATH /opt/local/lib/postgresql13/pkgconfig/

the build error disappeared.

[smichea]

i get similar error when trying to run the example in orm doc

builder error: 'libpq-fe.h' not found

I am on win11 and dont have postgres locally (i am using a remote instance)

[JalonSolov]

Even if your postgres server is remote, you still need to have the headers local for your build.

[smichea]

i managed to do that on wsl but not on windows.

[JalonSolov]

If you have the files in wsl, you should be able to copy them to Windows. The pg driver source in V has these lines for Windows:

	#flag windows -I @VEXEROOT/thirdparty/pg/include
	#flag windows -L @VEXEROOT/thirdparty/pg/win64

So the .h files would go to your <v install dir>/thirdparty/pg/include directory (which you'll need to create). Not sure what goes in the win64 subdir, but likely a dll that's part of the Windows version of postgresql client.

We definitely need better docs on this...