From 0d68c5dc39cb026328b2fe8cccce089e543af011 Mon Sep 17 00:00:00 2001
From: Alessio Pagliarulo <alessiopag@icloud.com>
Date: Thu, 29 Oct 2026 14:54:18 -0400
Subject: [PATCH] ci: make backend env cache deterministic

Two caches (mamba env and poetry venv) restored into the same env folder,
and the venv cache used restore-keys. On nextjs this mixed conda's
charset-normalizer 3.5.2 with poetry's 3.1.0, so the same commit passed
on the PR and failed on push (charset_normalizer.md has no CharInfo).

Use one cache keyed on environment.yml and poetry.lock with no partial
matches, and always run poetry install.
---
 .github/workflows/backend.yml | 68 ++++++++---------------------------
 1 file changed, 15 insertions(+), 53 deletions(-)

diff --git a/.github/workflows/backend.yml b/.github/workflows/backend.yml
index e25365e7..5c40f5d3 100644
--- a/.github/workflows/backend.yml
+++ b/.github/workflows/backend.yml
@@ -25,39 +25,20 @@ jobs:
           use-mamba: true
           activate-environment: dlp
 
-      - name: Cache Mamba env
-        id: cached-mamba-env
-        uses: actions/cache@v3
-        env:
-          # Increase this value to reset cache if etc/example-environment.yml has not changed
-          CACHE_NUMBER: 0
-        with:
-          path: /usr/share/miniconda3/envs/
-          key: mamba-${{ runner.os }}-${{env.CACHE_NUMBER }}-${{hashFiles('**/training/environment.yml') }}
-
-      - name: Update environment
-        run: mamba env update -n dlp -f
-          training/environment.yml
-        if: steps.cached-mamba-env.outputs.cache-hit != 'true'
-
-      #----------------------------------------------
-      #       load cached venv if cache exists
-      #----------------------------------------------
-      - name: Load cached venv
-        id: cached-poetry-dependencies
+      # One cache, keyed on both dependency files, no restore-keys: a hit is exactly the env these files built.
+      - name: Cache dlp env
+        id: cached-env
         uses: actions/cache@v3
         with:
           path: /usr/share/miniconda3/envs/dlp
-          key: training-venv-${{ runner.os }}-${{ hashFiles('**/training/poetry.lock') }}
-          restore-keys: training-venv-${{ runner.os }}-
+          key: dlp-env-${{ runner.os }}-1-${{ hashFiles('training/environment.yml', 'training/poetry.lock') }}
 
-      #---------------------------------------------------
-      #       install dependencies if cache does not exist
-      #---------------------------------------------------
+      - name: Update environment
+        if: steps.cached-env.outputs.cache-hit != 'true'
+        run: mamba env update -n dlp -f training/environment.yml
 
       - name: Install dependencies
-        if: steps.cached-poetry-dependencies.outputs.cache-hit != 'true'
-        run: pwd && cd training && poetry install --no-interaction --no-root && poetry env info -p
+        run: cd training && poetry install --no-interaction --no-root
         shell: bash -el {0}
 
       - name: Add Poetry env to PATH
@@ -106,38 +87,19 @@ jobs:
           use-mamba: true
           activate-environment: dlp
 
-      - name: Cache Mamba env
-        id: cached-mamba-env
+      # One cache, keyed on both dependency files, no restore-keys: a hit is exactly the env these files built.
+      - name: Cache dlp env
+        id: cached-env
         uses: actions/cache@v3
-        env:
-          # Increase this value to reset cache if etc/example-environment.yml has not changed
-          CACHE_NUMBER: 0
         with:
-          path: /usr/share/miniconda3/envs/
-          key: mamba-${{ runner.os }}-${{env.CACHE_NUMBER }}-${{hashFiles('**/training/environment.yml') }}
+          path: /usr/share/miniconda3/envs/dlp
+          key: dlp-env-${{ runner.os }}-1-${{ hashFiles('training/environment.yml', 'training/poetry.lock') }}
 
       - name: Update environment
-        run: mamba env update -n dlp -f
-          training/environment.yml
-        if: steps.cached-mamba-env.outputs.cache-hit != 'true'
+        if: steps.cached-env.outputs.cache-hit != 'true'
+        run: mamba env update -n dlp -f training/environment.yml
 
-      #----------------------------------------------
-      #       load cached venv if cache exists
-      #----------------------------------------------
-
-      - name: Load cached venv
-        id: cached-poetry-dependencies
-        uses: actions/cache@v3
-        with:
-          path: /usr/share/miniconda3/envs/dlp
-          key: training-venv-${{ runner.os }}-${{ hashFiles('**/training/poetry.lock') }}
-          restore-keys: training-venv-${{ runner.os }}-
-
-      #----------------------------------------------
-      # install dependencies if cache does not exist
-      #----------------------------------------------
       - name: Install dependencies
-        if: steps.cached-poetry-dependencies.outputs.cache-hit != 'true'
         run: cd training && poetry install --no-interaction --no-root
         shell: bash -el {0}