Issues with existing schema or insufficient schema creation priviledges

[cgauvi]

Thanks for the work, this is a useful tool.

Problem

Code fails with the following error if 1.user does not have schema creation rights or 2.the specified schema xxxx already exists

Executing SQL: 'create schema xxxx'
Error setting up gtfs schema

This comes from run_sql(conn, "create schema %s", arguments.schema)

By the way , the hard coded error message Error setting up gtfs schema is confusing since it does not change if a schema is specified

Removing that statement and passing in a valid existing schema works as expected.

To Reproduce

gtfs2pgrouting -d $dbname \
 -u $user \
 -p $password \
 -H $host \
 -P $port \
 -s xxxx \
 -t 'folder' \
 -v \
 data/gtfs

with existing xxxx schema

Expectation

I expect the code not to try to create the schema if it already exists. At least setting run_sql(conn, "create schema IF NOT EXISTS %s", arguments.schema) would be better, but this still fails if the user doesn't have proper access. I suggest simply removing this statement and sending out an error if the schema does not exist and asking the user to create if if desired.

Platform/versions

SELECT version(); 
SELECT postgis_full_version();
SELECT pgr_version(); 

PostgreSQL 16.8 on aarch64-unknown-linux-gnu, compiled by aarch64-unknown-linux-gnu-gcc (GCC) 10.5.0, 64-bit

POSTGIS="3.5.1 0" [EXTENSION] PGSQL="160" GEOS="3.13.0-CAPI-1.19.0" PROJ="9.5.0 GDAL="GDAL 3.9.3, released 2024/10/07" LIBXML="2.12.5" LIBJSON="0.15.99" LIBPROTOBUF="1.3.0" WAGYU="0.5.0 (Internal)"

pgr_version: 3.6.3