diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
index 80716af9c10f..1d41847172f3 100644
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -1,10 +1,33 @@
 {
-  "name": "Docusaurus Dev Container",
-  "image": "mcr.microsoft.com/vscode/devcontainers/typescript-node:14-buster",
+  "image": "mcr.microsoft.com/vscode/devcontainers/base:ubuntu-20.04",
   "settings": {
-    "terminal.integrated.shell.linux": "/bin/bash"
+    "[typescript]": {
+      "editor.defaultFormatter": "esbenp.prettier-vscode",
+      "editor.formatOnSave": true
+    },
+    "[json]": {
+      "editor.defaultFormatter": "esbenp.prettier-vscode",
+      "editor.formatOnSave": true
+    },
+    "[jsonc]": {
+      "editor.defaultFormatter": "esbenp.prettier-vscode",
+      "editor.formatOnSave": true
+    }
   },
-  "extensions": ["dbaeumer.vscode-eslint", "orta.vscode-jest"],
+  "extensions": [
+    "dbaeumer.vscode-eslint",
+    "orta.vscode-jest",
+    "esbenp.prettier-vscode",
+    "streetsidesoftware.code-spell-checker"
+  ],
   "forwardPorts": [3000],
-  "postCreateCommand": "yarn install"
+  "containerUser": "vscode",
+  "postCreateCommand": "yarn install",
+  "waitFor": "postCreateCommand", // otherwise automated jest tests fail
+  "features": {
+    "node": {
+      "version": "14"
+    },
+    "github-cli": "latest"
+  }
 }
diff --git a/.eslintrc.js b/.eslintrc.js
index 64f77872d6a1..d31aec2e0a19 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -49,6 +49,7 @@ module.exports = {
     curly: [WARNING, 'all'],
     'global-require': WARNING,
     'lines-between-class-members': OFF,
+    'max-classes-per-file': OFF,
     'max-len': [
       WARNING,
       {
diff --git a/jest.config.mjs b/jest.config.mjs
index d973ca87d2de..f47278a1c449 100644
--- a/jest.config.mjs
+++ b/jest.config.mjs
@@ -7,6 +7,8 @@
 
 import {fileURLToPath} from 'url';
 
+process.env.TZ = 'UTC';
+
 const ignorePatterns = [
   '/node_modules/',
   '__fixtures__',
diff --git a/package.json b/package.json
index fb186a2b162a..ef21905e1d61 100644
--- a/package.json
+++ b/package.json
@@ -52,7 +52,7 @@
     "lint:spelling": "cspell \"**\" --no-progress",
     "lint:style": "stylelint \"**/*.css\"",
     "lerna": "lerna",
-    "test": "cross-env TZ=UTC jest",
+    "test": "jest",
     "test:build:website": "./admin/scripts/test-release.sh",
     "watch": "yarn lerna run --parallel watch",
     "clear": "(yarn workspace website clear || echo 'Failure while running docusaurus clear') && yarn lerna exec --ignore docusaurus yarn rimraf lib lib-next",
diff --git a/packages/docusaurus-plugin-content-blog/src/blogUtils.ts b/packages/docusaurus-plugin-content-blog/src/blogUtils.ts
index ab24aa34ab92..a19f55d641fd 100644
--- a/packages/docusaurus-plugin-content-blog/src/blogUtils.ts
+++ b/packages/docusaurus-plugin-content-blog/src/blogUtils.ts
@@ -247,7 +247,7 @@ async function processBlogSourceFile(
       });
       return result.date;
     } catch (err) {
-      logger.error(err);
+      logger.warn(err);
       return (await fs.stat(blogSourceAbsolute)).birthtime;
     }
   }
diff --git a/packages/docusaurus-plugin-content-docs/src/__tests__/lastUpdate.test.ts b/packages/docusaurus-plugin-content-docs/src/__tests__/lastUpdate.test.ts
index 61e27d9014bd..17cfaba48e9f 100644
--- a/packages/docusaurus-plugin-content-docs/src/__tests__/lastUpdate.test.ts
+++ b/packages/docusaurus-plugin-content-docs/src/__tests__/lastUpdate.test.ts
@@ -47,7 +47,7 @@ describe('getFileLastUpdate', () => {
 
   it('non-existing file', async () => {
     const consoleMock = jest
-      .spyOn(console, 'error')
+      .spyOn(console, 'warn')
       .mockImplementation(() => {});
     const nonExistingFileName = '.nonExisting';
     const nonExistingFilePath = path.join(
@@ -65,10 +65,17 @@ describe('getFileLastUpdate', () => {
     consoleMock.mockRestore();
   });
 
-  it('temporary created file that has no git timestamp', async () => {
+  it('temporary created file that is not tracked by git', async () => {
+    const consoleMock = jest
+      .spyOn(console, 'warn')
+      .mockImplementation(() => {});
     const tempFilePath = path.join(__dirname, '__fixtures__', '.temp');
     await fs.writeFile(tempFilePath, 'Lorem ipsum :)');
     await expect(getFileLastUpdate(tempFilePath)).resolves.toBeNull();
+    expect(consoleMock).toHaveBeenCalledTimes(1);
+    expect(consoleMock).toHaveBeenLastCalledWith(
+      expect.stringMatching(/not tracked by git./),
+    );
     await fs.unlink(tempFilePath);
   });
 
diff --git a/packages/docusaurus-plugin-content-docs/src/lastUpdate.ts b/packages/docusaurus-plugin-content-docs/src/lastUpdate.ts
index e62cfe309360..ae12fb244b1d 100644
--- a/packages/docusaurus-plugin-content-docs/src/lastUpdate.ts
+++ b/packages/docusaurus-plugin-content-docs/src/lastUpdate.ts
@@ -6,11 +6,16 @@
  */
 
 import logger from '@docusaurus/logger';
-import {getFileCommitDate, GitNotFoundError} from '@docusaurus/utils';
+import {
+  getFileCommitDate,
+  FileNotTrackedError,
+  GitNotFoundError,
+} from '@docusaurus/utils';
 
 type FileLastUpdateData = {timestamp?: number; author?: string};
 
 let showedGitRequirementError = false;
+let showedFileNotTrackedError = false;
 
 export async function getFileLastUpdate(
   filePath?: string,
@@ -31,8 +36,16 @@ export async function getFileLastUpdate(
     if (err instanceof GitNotFoundError && !showedGitRequirementError) {
       logger.warn('Sorry, the docs plugin last update options require Git.');
       showedGitRequirementError = true;
+    } else if (
+      err instanceof FileNotTrackedError &&
+      !showedFileNotTrackedError
+    ) {
+      logger.warn(
+        'Cannot infer the update date for some files, as they are not tracked by git.',
+      );
+      showedFileNotTrackedError = true;
     } else {
-      logger.error(err);
+      logger.warn(err);
     }
     return null;
   }
diff --git a/packages/docusaurus-utils/src/gitUtils.ts b/packages/docusaurus-utils/src/gitUtils.ts
index 7325964b6dd4..204b3f564d88 100644
--- a/packages/docusaurus-utils/src/gitUtils.ts
+++ b/packages/docusaurus-utils/src/gitUtils.ts
@@ -10,6 +10,8 @@ import shell from 'shelljs';
 
 export class GitNotFoundError extends Error {}
 
+export class FileNotTrackedError extends Error {}
+
 export const getFileCommitDate = (
   file: string,
   {
@@ -70,6 +72,13 @@ export const getFileCommitDate = (
   }
 
   const output = result.stdout.trim();
+
+  if (!output) {
+    throw new FileNotTrackedError(
+      `Failed to retrieve the git history for file "${file}" because the file is not tracked by git.`,
+    );
+  }
+
   const match = output.match(regex);
 
   if (
diff --git a/packages/docusaurus-utils/src/index.ts b/packages/docusaurus-utils/src/index.ts
index 26cb7ae65756..c3e246ce8d5c 100644
--- a/packages/docusaurus-utils/src/index.ts
+++ b/packages/docusaurus-utils/src/index.ts
@@ -21,7 +21,11 @@ export {
   WEBPACK_URL_LOADER_LIMIT,
 } from './constants';
 export {generate, genChunkName, readOutputHTMLFile} from './emitUtils';
-export {getFileCommitDate, GitNotFoundError} from './gitUtils';
+export {
+  getFileCommitDate,
+  FileNotTrackedError,
+  GitNotFoundError,
+} from './gitUtils';
 export {
   mergeTranslations,
   updateTranslationFileMessages,
diff --git a/project-words.txt b/project-words.txt
index ae29fa0b5180..f71fab6a6ca2 100644
--- a/project-words.txt
+++ b/project-words.txt
@@ -53,11 +53,13 @@ customizability
 daishi
 datagit
 datas
+dbaeumer
 décembre
 dedup
 deduplicated
 déja
 deps
+devcontainers
 devspace
 devto
 dmitry
@@ -78,6 +80,7 @@ endilie
 endiliey
 entrypoints
 errnametoolong
+esbenp
 esbuild
 eslintcache
 evaluable
@@ -98,8 +101,8 @@ globby
 goss
 goyal
 gtag
-hardcoding
 hahaha
+hardcoding
 héctor
 héllô
 heuristical
@@ -184,6 +187,7 @@ opensearch
 opensearchdescription
 optimizt
 optind
+orta
 overrideable
 pageview
 palenight
@@ -296,6 +300,7 @@ typesense
 unflat
 unist
 unlocalized
+unmatch
 unnormalized
 unoptimized
 unprefixed