diff --git a/distbuild/pkg/api/heartbeat_handler.go b/distbuild/pkg/api/heartbeat_handler.go
index 6c7629b..c335a54 100644
--- a/distbuild/pkg/api/heartbeat_handler.go
+++ b/distbuild/pkg/api/heartbeat_handler.go
@@ -29,7 +29,7 @@ func (h *HeartbeatHandler) doHeartbeat(w http.ResponseWriter, r *http.Request) e
 	}
 
 	var req HeartbeatRequest
-	if err := json.Unmarshal(reqJSON, &req); err != nil {
+	if err = json.Unmarshal(reqJSON, &req); err != nil {
 		return err
 	}
 
diff --git a/distbuild/pkg/artifact/cache_test.go b/distbuild/pkg/artifact/cache_test.go
index faf88c4..b4a3801 100644
--- a/distbuild/pkg/artifact/cache_test.go
+++ b/distbuild/pkg/artifact/cache_test.go
@@ -18,8 +18,8 @@ type testCache struct {
 	tmpDir string
 }
 
-func (c *testCache) cleanup() error {
-	return os.RemoveAll(c.tmpDir)
+func (c *testCache) cleanup() {
+	_ = os.RemoveAll(c.tmpDir)
 }
 
 func newTestCache(t *testing.T) *testCache {
diff --git a/distbuild/pkg/artifact/client.go b/distbuild/pkg/artifact/client.go
index c26be3e..4ad79e7 100644
--- a/distbuild/pkg/artifact/client.go
+++ b/distbuild/pkg/artifact/client.go
@@ -16,7 +16,7 @@ func Download(ctx context.Context, endpoint string, c *Cache, artifactID build.I
 	if err != nil {
 		return err
 	}
-	defer abort()
+	defer func() { _ = abort() }()
 
 	req, err := http.NewRequestWithContext(ctx, http.MethodGet, endpoint+"/artifact?id="+artifactID.String(), nil)
 	if err != nil {
diff --git a/distbuild/pkg/client/build.go b/distbuild/pkg/client/build.go
index 7979c06..92943a7 100644
--- a/distbuild/pkg/client/build.go
+++ b/distbuild/pkg/client/build.go
@@ -66,7 +66,7 @@ func (c *Client) Build(ctx context.Context, graph build.Graph, lsn BuildListener
 	}
 
 	c.l.Debug("build started", zap.String("build_id", started.ID.String()))
-	if err := c.uploadSources(ctx, &graph, started); err != nil {
+	if err = c.uploadSources(ctx, &graph, started); err != nil {
 		return err
 	}
 
diff --git a/distbuild/pkg/filecache/client.go b/distbuild/pkg/filecache/client.go
index f422919..3e82e97 100644
--- a/distbuild/pkg/filecache/client.go
+++ b/distbuild/pkg/filecache/client.go
@@ -56,7 +56,7 @@ func (c *Client) Download(ctx context.Context, localCache *Cache, id build.ID) e
 	if err != nil {
 		return err
 	}
-	defer abort()
+	defer func() { _ = abort() }()
 
 	req, err := http.NewRequestWithContext(ctx, http.MethodGet, c.endpoint+"/file?id="+id.String(), nil)
 	if err != nil {
diff --git a/distbuild/pkg/filecache/client_test.go b/distbuild/pkg/filecache/client_test.go
index a0d852a..79c13c4 100644
--- a/distbuild/pkg/filecache/client_test.go
+++ b/distbuild/pkg/filecache/client_test.go
@@ -31,7 +31,7 @@ func newEnv(t *testing.T) *env {
 	cache := newCache(t)
 	defer func() {
 		if cache != nil {
-			_ = cache.cleanup()
+			cache.cleanup()
 		}
 	}()
 
@@ -54,7 +54,7 @@ func newEnv(t *testing.T) *env {
 
 func (e *env) stop() {
 	e.server.Close()
-	_ = e.cache.cleanup()
+	e.cache.cleanup()
 }
 
 func TestFileUpload(t *testing.T) {
@@ -99,11 +99,11 @@ func TestFileUpload(t *testing.T) {
 			var wg sync.WaitGroup
 			wg.Add(G)
 
+			id := build.ID{0x03, byte(i)}
 			for j := 0; j < G; j++ {
 				go func() {
 					defer wg.Done()
 
-					id := build.ID{0x03, byte(j)}
 					assert.NoError(t, env.client.Upload(ctx, id, tmpFilePath))
 				}()
 			}
@@ -124,7 +124,7 @@ func TestFileDownload(t *testing.T) {
 
 	w, abort, err := env.cache.Write(id)
 	require.NoError(t, err)
-	defer abort()
+	defer func() { _ = abort() }()
 
 	_, err = w.Write([]byte("foobar"))
 	require.NoError(t, err)
diff --git a/distbuild/pkg/filecache/filecache_test.go b/distbuild/pkg/filecache/filecache_test.go
index 6575b04..1d0d8a7 100644
--- a/distbuild/pkg/filecache/filecache_test.go
+++ b/distbuild/pkg/filecache/filecache_test.go
@@ -27,8 +27,8 @@ func newCache(t *testing.T) *testCache {
 	return &testCache{Cache: c, tmpDir: tmpDir}
 }
 
-func (c *testCache) cleanup() error {
-	return os.Remove(c.tmpDir)
+func (c *testCache) cleanup() {
+	_ = os.Remove(c.tmpDir)
 }
 
 func TestFileCache(t *testing.T) {
diff --git a/distbuild/pkg/filecache/handler.go b/distbuild/pkg/filecache/handler.go
index a829350..ddd21c2 100644
--- a/distbuild/pkg/filecache/handler.go
+++ b/distbuild/pkg/filecache/handler.go
@@ -59,7 +59,7 @@ func (h *Handler) doPut(w http.ResponseWriter, r *http.Request, id build.ID) err
 		} else if err != nil {
 			return nil, err
 		}
-		defer abort()
+		defer func() { _ = abort() }()
 
 		if _, err = io.Copy(w, r.Body); err != nil {
 			return nil, err
diff --git a/distbuild/pkg/worker/download.go b/distbuild/pkg/worker/download.go
index 2c2c4d6..aaa73b2 100644
--- a/distbuild/pkg/worker/download.go
+++ b/distbuild/pkg/worker/download.go
@@ -12,7 +12,7 @@ func (w *Worker) pullFiles(ctx context.Context, files map[build.ID]string) error
 	for id := range files {
 		_, unlock, err := w.fileCache.Get(id)
 		if errors.Is(err, filecache.ErrNotFound) {
-			if err := w.fileClient.Download(ctx, w.fileCache, id); err != nil {
+			if err = w.fileClient.Download(ctx, w.fileCache, id); err != nil {
 				return err
 			}
 		} else if err != nil {
diff --git a/distbuild/pkg/worker/job.go b/distbuild/pkg/worker/job.go
index 631b546..8c2334c 100644
--- a/distbuild/pkg/worker/job.go
+++ b/distbuild/pkg/worker/job.go
@@ -165,7 +165,7 @@ func (w *Worker) runJob(ctx context.Context, spec *api.JobSpec) (*api.JobResult,
 		return res, nil
 	}
 
-	if err := w.pullFiles(ctx, spec.SourceFiles); err != nil {
+	if err = w.pullFiles(ctx, spec.SourceFiles); err != nil {
 		return nil, err
 	}