Ensemble Manager: a ZIP component cannot run on Tapis, and the failure is an opaque 500

[mosoriob]

Problem

A ZIP component and the Tapis engine are not compatible. This is known and it is not new.
The defect is that nothing handles it. The user gets a 500 with a JSON parser message.

Measured live at TACC on 2026-08-09, signed in as mosorio@portals:

POST https://ensemble-manager.mint.tacc.utexas.edu/v1/executionEngines/tapis  ->  500
{"error":"Unexpected token 'P', \"PK...\" is not valid JSON"}

PK followed by bytes 03 04 is the ZIP magic number.

Cause

When the engine is Tapis, ExecutionCreation.ts:225 calls loadComponentFromTapis(model.code_url).
That method fetches has_component_location and runs await response.json(), then reads
result. It expects the Tapis Apps API envelope — a Tapis app definition.

The model was HAND Setup for Hays catchment. Its component location is a MINT localex bundle:

https://github.com/mintproject/HAND-TauDEM/raw/v2.1.4/hand_v2_mint_component.zip

So response.json() parses a ZIP and throws. The error escapes as a plain 500.

The input dataset is not involved. The submit was repeated with a GeoTIFF input instead of a
ZIP input. The response was identical, byte for byte — same etag, same content-length.

Scale at TACC

315 model configurations:

has_component_location	Count
.zip (localex bundle)	171
empty	105
.cwl	19
Tapis app URL	17

So 171 configurations will 500 on a Tapis deployment, and TACC runs Tapis
(execution_engine.type: tapis in the Helm values; the Lit config sets
REACT_APP_EXECUTION_ENGINE = "tapis").

Only 5 of the 17 Tapis app URLs are on the portals tenant with data annotated in CKAN.

The single successful tapis execution at TACC is from 2025-05-16, older than this code
path. Every execution since is localex.

Asks

1. Fail with a clear message. Detect that the component is not a Tapis app before parsing.
   Return the reason, not a parser error. This alone turns an unexplainable 500 into an
   answerable one.
2. Say which engines a configuration supports. The catalog does not record it. Today the
   only way to know is to read the file extension of has_component_location.
3. Decide whether a ZIP component should be registered as a Tapis app, or whether Tapis
   deployments should hide the configurations they cannot run.

Context

Found while resolving #92. It does not
block #92, which picks a Tapis-ready configuration instead. It is pre-existing and the Lit UI
behaves the same, so it is not a ui-react regression and it does not block the flip
(#77). Filed so it is not lost.