Problem with defaults/main.yml syntax

Role fails with this error:

ERROR! We were unable to read either as JSON nor YAML, these are the errors we got from each:
JSON: Expecting value: line 1 column 1 (char 0)

Syntax Error while loading YAML.
  found character '\t' that cannot start any token

The error appears to be in '/nvme1/work/git-repos/__ansible-roles/anxs.postgresql/defaults/main.yml': line 236, column 42, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

postgresql_bgwriter_lru_multiplier: 2.0    # 0-10.0 multiplier on buffers scanned/round
postgresql_bgwriter_flush_after:    512kB               # measured in pages, 0 disables
                                         ^ here
There appears to be a tab character at the start of the line.

YAML does not use tabs for formatting. Tabs should be replaced with spaces.

For example:
    - name: update tooling
      vars:
        version: 1.2.3
#    ^--- there is a tab there.

Should be written as:
    - name: update tooling
      vars:
        version: 1.2.3
# ^--- all spaces here.
task: Failed to run task "pb": exit status 4

ANXS / postgresql

Problem with defaults/main.yml syntax #549