Fix spawn starting the viewer even if logging is disabled (#5284)

### What

* Fixes #5261

### Checklist
* [x] I have read and agree to [Contributor
Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)
* [x] I've included a screenshot or gif (if applicable)
* [x] I have tested the web demo (if applicable):
* Using newly built examples:
[app.rerun.io](https://app.rerun.io/pr/5284/index.html)
* Using examples from latest `main` build:
[app.rerun.io](https://app.rerun.io/pr/5284/index.html?manifest_url=https://app.rerun.io/version/main/examples_manifest.json)
* Using full set of examples from `nightly` build:
[app.rerun.io](https://app.rerun.io/pr/5284/index.html?manifest_url=https://app.rerun.io/version/nightly/examples_manifest.json)
* [x] The PR title and labels are set such as to maximize their
usefulness for the next release's CHANGELOG
* [x] If applicable, add a new check to the [release
checklist](https://github.com/rerun-io/rerun/blob/main/tests/python/release_checklist)!

- [PR Build Summary](https://build.rerun.io/pr/5284)
- [Docs
preview](https://rerun.io/preview/c659f5a29d6a439bcf11756099e7e9338561774a/docs)
<!--DOCS-PREVIEW-->
- [Examples
preview](https://rerun.io/preview/c659f5a29d6a439bcf11756099e7e9338561774a/examples)
<!--EXAMPLES-PREVIEW-->
- [Recent benchmark results](https://build.rerun.io/graphs/crates.html)
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crates/re_sdk/src/recording_stream.rs

@@ -432,6 +432,11 @@ impl RecordingStreamBuilder {
         opts: &crate::SpawnOptions,
         flush_timeout: Option<std::time::Duration>,
     ) -> RecordingStreamResult<RecordingStream> {
+        if !self.is_enabled() {
+            re_log::debug!("Rerun disabled - call to spawn() ignored");
+            return Ok(RecordingStream::disabled());
+        }
+
         let connect_addr = opts.connect_addr();
 
         // NOTE: If `_RERUN_TEST_FORCE_SAVE` is set, all recording streams will write to disk no matter
@@ -517,18 +522,19 @@ impl RecordingStreamBuilder {
     /// This can be used to then construct a [`RecordingStream`] manually using
     /// [`RecordingStream::new`].
     pub fn into_args(self) -> (bool, StoreInfo, DataTableBatcherConfig) {
+        let enabled = self.is_enabled();
+
         let Self {
             application_id,
             store_kind,
             store_id,
             store_source,
-            default_enabled,
-            enabled,
+            default_enabled: _,
+            enabled: _,
             batcher_config,
             is_official_example,
         } = self;
 
-        let enabled = enabled.unwrap_or_else(|| crate::decide_logging_enabled(default_enabled));
         let store_id = store_id.unwrap_or(StoreId::random(store_kind));
         let store_source = store_source.unwrap_or_else(|| StoreSource::RustSdk {
             rustc_version: env!("RE_BUILD_RUSTC_VERSION").into(),
@@ -555,6 +561,12 @@ impl RecordingStreamBuilder {
 
         (enabled, store_info, batcher_config)
     }
+
+    /// Internal check for whether or not logging is enabled using explicit/default settings & env var.
+    fn is_enabled(&self) -> bool {
+        self.enabled
+            .unwrap_or_else(|| crate::decide_logging_enabled(self.default_enabled))
+    }
 }
 
 // ----------------------------------------------------------------------------
@@ -1350,6 +1362,10 @@ impl RecordingStream {
         opts: &crate::SpawnOptions,
         flush_timeout: Option<std::time::Duration>,
     ) -> RecordingStreamResult<()> {
+        if !self.is_enabled() {
+            re_log::debug!("Rerun disabled - call to spawn() ignored");
+            return Ok(());
+        }
         if forced_sink_path().is_some() {
             re_log::debug!("Ignored setting new TcpSink since _RERUN_FORCE_SINK is set");
             return Ok(());

rerun_py/rerun_sdk/rerun/sinks.py

@@ -231,6 +231,10 @@ def spawn(
 
     """
 
+    if not bindings.is_enabled():
+        logging.warning("Rerun is disabled - spawn() call ignored.")
+        return
+
     import os
     import subprocess
     import sys