message: Cypress: only pass -u arg to docker on *nix systems
diff: @@ -112,6 +112,12 @@ async function synapseStart(template: string): Promise<SynapseInstance> {
  const containerName = `react-sdk-cypress-synapse-${crypto.randomBytes(4).toString("hex")}`;
  const userInfo = os.userInfo();
  + let userParams: string[] = [];
  + if (userInfo.uid >= 0) {
  + // On *nix we run the docker container as our uid:gid otherwise cleaning it up its media_store can be difficult
  + userParams = ["-u", `${userInfo.uid}:${userInfo.gid}`];
  + }
  +
  const synapseId = await new Promise<string>((resolve, reject) => {
  childProcess.execFile('docker', [
  "run",
  @@ -119,8 +125,7 @@ async function synapseStart(template: string): Promise<SynapseInstance> {
  "-d",
  "-v", `${synCfg.configDir}:/data`,
  "-p", `${synCfg.port}:8008/tcp`,
  - // We run the docker container as our uid:gid otherwise cleaning it up its media_store can be difficult
  - "-u", `${userInfo.uid}:${userInfo.gid}`,
  + ...userParams,
  "matrixdotorg/synapse:develop",
  "run",
  ], (err, stdout) => {
  