From 3ee14659de0dd55c4c09bec4b1dbe09c26f058f4 Mon Sep 17 00:00:00 2001
From: Vasili Pascal <vasili.pascal@gmail.com>
Date: Mon, 21 Sep 2026 20:49:02 +0300
Subject: [PATCH] ci: stop caching the Rust target directory in the docker
 workflow
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The build filled the runner's disk and died in post-job cleanup:

  Unhandled exception. System.IO.IOException: No space left on device

Every check had passed — cargo check, the test suite, the BDD suite,
rustfmt, all four release binaries. The job only failed while saving its
cache, after 33 minutes.

`actions/cache` was storing the whole `target` directory, and
`restore-keys: docker-` meant each run started from an older, already
bloated cache, added to it, and saved a larger one — so every run raised
the next one's floor. For a workspace building five binaries in both
debug and release that ratchets past the ~14 GB a runner has free.

Replaced with Swatinem/rust-cache, caching registry and git only.
rust.yml already made this exact call, with a comment explaining why;
the two workflows now follow one rule.

The trade-off is a slower docker workflow, since compilation output is
no longer reused between runs. That is the right side to err on: a slow
pipeline is an inconvenience, a pipeline that cannot finish is not.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
---
 .github/workflows/docker.yml | 38 ++++++++++++------------------------
 1 file changed, 13 insertions(+), 25 deletions(-)

diff --git a/.github/workflows/docker.yml b/.github/workflows/docker.yml
index 2a9150c3..8ddc86d1 100644
--- a/.github/workflows/docker.yml
+++ b/.github/workflows/docker.yml
@@ -66,23 +66,20 @@ jobs:
           override: true
           components: rustfmt, clippy
 
-      - name: Cache cargo registry
-        uses: actions/cache@v4
+      # Registry and git only — not `target`. Caching the target directory here
+      # filled the runner's disk: `restore-keys: docker-` pulled in an older,
+      # already-bloated cache, the build added to it, and the post-job step
+      # saved a larger one still, so every run grew the next one's starting
+      # point. A 33-minute job that passed every check then died in cleanup
+      # with "No space left on device".
+      #
+      # rust.yml reached the same conclusion for the same reason; this keeps
+      # both workflows on one rule.
+      - name: Cache Cargo registry/git (no target — it grows without bound here)
+        uses: Swatinem/rust-cache@v2
         with:
-          path: ~/.cargo/registry
-          key: docker-registry-${{ hashFiles('**/Cargo.lock') }}
-          restore-keys: |
-            docker-registry-
-            docker-
-
-      - name: Cache cargo index
-        uses: actions/cache@v4
-        with:
-          path: ~/.cargo/git
-          key: docker-index-${{ hashFiles('**/Cargo.lock') }}
-          restore-keys: |
-            docker-index-
-            docker-
+          cache-targets: "false"
+          key: docker-cicd
 
       - name: Generate Secret Key
         run: |
@@ -99,15 +96,6 @@ jobs:
           echo "PostgreSQL did not become ready in time" >&2
           exit 1
 
-      - name: Cache cargo build
-        uses: actions/cache@v4
-        with:
-          path: target
-          key: docker-build-${{ hashFiles('**/Cargo.lock') }}
-          restore-keys: |
-            docker-build-
-            docker-
-
       - name: Cargo check
         uses: actions-rs/cargo@v1
         with: