The scraper crashes while making the final aggregate:
```
mix run pipeline.exs
15:05:02.499 [error] Failed: ./reports/all-wikis-20230601-summary.csv
Overall progress 773/773 [≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡] 100%
** (YamlElixir.ParsingError) malformed yaml
(yaml_elixir 2.9.0) lib/yaml_elixir.ex:22: YamlElixir.read_from_file!/2
(scrape_wiki_dump 0.1.0) lib/pipeline.ex:96: anonymous fn/1 in Wiki.DumpPipeline.aggregate_across_wikis/1
(elixir 1.14.3) lib/enum.ex:1658: Enum."-map/2-lists^map/1-0-"/2
(elixir 1.14.3) lib/enum.ex:1658: Enum."-map/2-lists^map/1-0-"/2
(scrape_wiki_dump 0.1.0) lib/checkpointer.ex:120: anonymous fn/3 in Wiki.Checkpointer.run_once/4
(scrape_wiki_dump 0.1.0) lib/checkpointer.ex:134: Wiki.Checkpointer.report_progress/2
(scrape_wiki_dump 0.1.0) lib/checkpointer.ex:116: Wiki.Checkpointer.run_once/4
```
Debugging is showing that the arwikinews summary is the file causing the crash, however the YAML file is read correctly when the same library call is made from the commandline:
```
iex -S mix
YamlElixir.read_from_file!("reports/arwikinews-20230601-summary.yaml")
```
Needs more investigation...
```