[HughRunyan]

Bug

A city DST Custom Location in Kosovo answers HTTP 500 on wastemap.earth, and the site tool's prefill for a point in Kosovo returns Serbia.

_iso3_for (in city_params.py) turns the caller's country into the ISO3 code SWEET's defaults are keyed by. It asked pycountry first, and pycountry has no Kosovo:

• By code it raised. XKX, the code SWEET's own tables and WasteMAP's country list use, gave LookupError, so City.dst_baseline_blank and City.cityparams_obj_for_blank_site raised ValueError("Country 'XKX' not found."). defaults_2019.region_lookup_iso3["XKX"] is "Southern Europe", so SWEET had the defaults; only the lookup failed.
• By name it was Serbia. search_fuzzy("Kosovo") returns Serbia, whose province Kosovo-Metohija matches. sdst_prepopulate names the country with the geocoder's English name, so a point in Kosovo was prefilled, and then modelled, as Serbia. The same search resolves "Curacao" to the Netherlands, and finds nothing for Macau, Pitcairn Islands, Svalbard and Jan Mayen Islands, US Minor Islands, or French Southern and Antarctic Lands.

Environment: prod API (api.wastemap.earth), SWEET_python main d5c592e, pycountry 26.2.16.

Reproduction (read-only GET):

curl -sG https://api.wastemap.earth/v1/city_emissions/city_baseline_parameters_v1_5 --data-urlencode "city_name=*" --data-urlencode country=XKX --data-urlencode population=2000000 --data-urlencode precipitation=500 --data-urlencode temperature=25

Expected: a baseline, as for country=PAK.
Actual: Internal Server Error (HTTP 500). Locally: City("*").dst_baseline_blank("XKX", 2_000_000, 500.0, 25.0) raises ValueError: Country 'XKX' not found.

Fix

_iso3_for tries SWEET's own table first: by code (defaults_2019.region_lookup_iso3), then by name (defaults_2019.country_to_iso3), ignoring case as pycountry does. Anything else goes to pycountry as before, so the exact-before-fuzzy order that fixed "MUS" (#71) stands.

Effect (model-output change for a country given by name)

Checked by running dst_baseline_blank for every code WasteMAP's /v1/dst_countries offers, before and after:

	before	after
XKX (Kosovo), 2040, 2M people, 500 mm, 25 °C	ValueError	38,771 t CH4
"Kosovo" by name	Serbia: 26,818 t	38,771 t
other 249 codes	—	bit-identical (each already resolved to itself)
site-tool prefill, point in Kosovo	SRB; food 44.3%, k 0.143, growth −0.76%/yr	XKX; Southern Europe's composition (food 35.7%), k 0.333, Kosovo's growth −0.08%/yr

Kosovo has no country rows in SWEET's defaults, so it takes Southern Europe's regional ones. It does have its own UN population series, which it now grows with. Climate TRACE's pipeline is unaffected: only dst_baseline_blank, cityparams_obj_for_blank_site and sdst_prepopulate call _iso3_for, and all three are WasteMAP paths.

Tests

tests/test_country_lookup.py (14 of its 17 fail on main):

• dst_baseline_blank("XKX", 2_000_000, 500.0, 25.0) builds a city that grows with Kosovo's population.
• cityparams_obj_for_blank_site(country="XKX", …) builds.
• sdst_prepopulate for a point in Pristina returns XKX, not SRB. The geocoder and database are faked, so it runs offline.
• Every code and every name in SWEET's own table resolves to SWEET's code; a country that doesn't exist still raises.

Full suite: 289 passed (Python 3.13 locally; CI runs 3.12).

Paired PR

RMI/WasteMAP#857, on the same branch name, so WasteMAP CI installs this branch. It makes both city DST endpoints answer 400 rather than 500 for a country SWEET can't find, and its fast tests run a Custom Location for every country the DST offers. Merge this one first.

Notes for review

• PR A Custom Location buries or dumps its waste in every country #74 changelog goes stale. Its entry says "Kosovo's XKX can't be looked up, before or after", and counts 249 countries. If this merges first, those lines need updating when A Custom Location buries or dumps its waste in every country #74 is rebased; with both, Kosovo takes Southern Europe's regional disposal split.
• changelog/2026-10.md doesn't exist on main. City DST scenarios run for São Paulo and Brasília: load_csv_new normalizes a city's composition #73, A Custom Location buries or dumps its waste in every country #74, Moving waste to a city's existing gas capture changes its emissions #75 and this PR each create it, so whichever merges second resolves a simple conflict.
• Not fixed here: the fuzzy search also turns junk input into a real country ("" → GBR, "None" → ITA). None of WasteMAP's frontends send those, so I've left it for a separate change.

Acceptance criteria

• City("*").dst_baseline_blank("XKX", 2_000_000, 500.0, 25.0) builds a city.
• _iso3_for resolves every code and name in SWEET's own table to SWEET's code, Kosovo included.
• The site tool's prefill for a point in Kosovo returns XKX.
• Every other code WasteMAP offers gives bit-identical output.
• Changelog updated (changelog/2026-10.md, changelog/README.md).

Definition of Done

Acceptance criteria met · tests & checks pass · docs (changelog) updated · reviewed & merged.

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