Alpine build error due changes to proj

[BWibo]

Build fails because due to changes to proj alpine package:
See here:

• https://gitlab.alpinelinux.org/alpine/aports/issues/10612
• timescale/timescaledb-docker#75
• postgis/docker-postgis#146

[jrzerr]

Stumbled across this issue due to my own problems with the alpine postgis build. I had to compile proj 4.9.3 from scratch (the version recommended for postgis 2.5.2 I was using), then point postgis configure to the src directory using --with-projdir.

[BWibo]

Thx, for your feedback, I was considering doing that as well. Its good to know you can confirm this works.

However, I might as well wait just for PostGIS 3.0 which is being released soon. According to this PostGIS 3 is going to support the proj 6+.

[BWibo]

Resolved by updating to postgresql-12 and postgis 3.0 in db171a8.