We cancelled a web application upgrade part way through when it was realized
Postgres needed a version upgrade first. Using the dump file extracted from
a full dump with pg_dumpall the DB was restored with a line like :
psql -d dbname -f dump.sql
The file dump.sql was extracted from the full dump using the script
pg_extract.sh script provided on Github by someone (not sure which fork).
Others may want to take note, this tool does not include the declaration
of TABLESPACE and its location. So the tablespace files will be
in the general data area. \db+ reports tablespace is defined, but it's
just empty. If you have a CREATE TABLESPACE with LOCATION in your full
dump, you should add it back into the extracted result for a single DB.