find_executable: checking for pg_config... -------------------- no

--------------------

find_header: checking for libpq-fe.h... -------------------- no

"gcc -o conftest -I/usr/local/rvm/rubies/ruby-2.7.4/include/ruby-2.7.0/x86_64-linux -I/usr/local/rvm/rubies/ruby-2.7.4/include/ruby-2.7.0/ruby/backward -I/usr/local/rvm/rubies/ruby-2.7.4/include/ruby-2.7.0 -I.    -g -O2 -fPIC conftest.c  -L. -L/usr/local/rvm/rubies/ruby-2.7.4/lib -Wl,-rpath,/usr/local/rvm/rubies/ruby-2.7.4/lib -L. -fstack-protector-strong -rdynamic -Wl,-export-dynamic     -Wl,-rpath,/usr/local/rvm/rubies/ruby-2.7.4/lib -L/usr/local/rvm/rubies/ruby-2.7.4/lib -lruby  -lm   -lc"
checked program was:
/* begin */
1: #include "ruby.h"
2: 
3: int main(int argc, char **argv)
4: {
5:   return !!argv[argc];
6: }
/* end */

"gcc -E -I/usr/local/rvm/rubies/ruby-2.7.4/include/ruby-2.7.0/x86_64-linux -I/usr/local/rvm/rubies/ruby-2.7.4/include/ruby-2.7.0/ruby/backward -I/usr/local/rvm/rubies/ruby-2.7.4/include/ruby-2.7.0 -I.    -g -O2 -fPIC  conftest.c -o conftest.i"
conftest.c:3:10: fatal error: libpq-fe.h: No such file or directory
 #include <libpq-fe.h>
          ^~~~~~~~~~~~
compilation terminated.
checked program was:
/* begin */
1: #include "ruby.h"
2: 
3: #include <libpq-fe.h>
/* end */

--------------------