checks failed

https://travis-ci.org/lib/pq/jobs/217185835 looks like an intermittent issue

i don't understand https://travis-ci.org/lib/pq/jobs/217185858

I don't think it's kosher for a library to write to stderr like this.

If we want warnings there should probably be a separate interface for that (but the sql.DB interface makes that a bit cumbersome, here, again).

i agree that it's not nice for a library to log warnings this way. i couldn't find any mechanism that was already in use for warnings, though

do you think this driver could either

• receive a callback function or a Writer or a Logger for sending warnings back, or
• offer a way to let library users specify that they want hard errors if pgpass can't be used

then again, this is exactly what the official libpq does:

$ cat main.c
#include <err.h>
#include <stdlib.h>

#include <postgresql/libpq-fe.h>

int main() {
  PGconn *pg;
  pg = PQconnectdb("dbname=postgres");

  if (PQstatus(pg) != CONNECTION_OK)
    errx(EXIT_FAILURE, "PostgreSQL connection failed: %s", PQerrorMessage(pg));

  fprintf(stderr, "success!\n");

  return EXIT_SUCCESS;
}
$ gcc main.c -lpq
$ chmod 640 ~/.pgpass
$ ./a.out
WARNING: password file "/home/mastensg/.pgpass" has group or world access; permissions should be u=rw (0600) or less
success!
$

@martinatsynqfm could you please take a look at this issue? Approach with PGPASSFILE on windows doesn't work at all because of incorrect permissions check mentioned in this PR.