Startup failure "s32 field doesn't match size: expected 4, actual 8" with PostgreSQL

[whitslack]

Issue and Steps to Reproduce

Attempting to start C-Lightning 0.9.1 using the PostgreSQL backend results in the following fatal error:

s32 field doesn't match size: expected 4, actual 8

Tracing with GDB reveals that this message is coming from the new fillin_missing_channel_id function at line 1256.

The channels.id column is of type BIGSERIAL (i.e., BIGINT), but the db_postgres_column_int function enforces that the column width is 4 bytes. This obviously fails.

Workaround

1. Change the channels.id column type to INTEGER.

   ALTER TABLE channels ALTER COLUMN id TYPE INTEGER;
   

2. Start lightningd so that the database upgrade can occur. The process will eventually fail to start with the following fatal error:

   u64 field doesn't match size: expected 8, actual 4
   

3. Change the channels.id column type back to BIGINT.

   ALTER TABLE channels ALTER COLUMN id TYPE BIGINT;
   

4. Start lightningd as normal.

[martinbehrens]

Able to replicate with v0.9.0 and v0.9.1 exactly as described. Workaround works as well, thanks @whitslack

[gabridome]

Nope. The workaround didn't work for me.
I have tried with 0.9.1.
I have executed point 1., point 2., obtained the same message, executed point 3. but, when I restart lightningd, I always have

s32 field doesn't match size: expected 4, actual 8 .

I also made a git pull to the last commit on master but the result is the same.