diff --git a/lib/entry-points.js b/lib/entry-points.js
index 841bb36a1..9e674a2c1 100644
--- a/lib/entry-points.js
+++ b/lib/entry-points.js
@@ -166182,6 +166182,17 @@ var Env = class extends ReadOnlyEnv {
       core.exportVariable(name, val);
     }
   }
+  /**
+   * Set some initial environment variables that we can set even without
+   * knowing what version of CodeQL we're running.
+   */
+  initialise(version) {
+    this.export("CODEQL_ACTION_FEATURE_MULTI_LANGUAGE" /* FEATURE_MULTI_LANGUAGE */, "false");
+    this.export("CODEQL_ACTION_FEATURE_SANDWICH" /* FEATURE_SANDWICH */, "false");
+    this.export("CODEQL_ACTION_FEATURE_SARIF_COMBINE" /* FEATURE_SARIF_COMBINE */, "true");
+    this.export("CODEQL_ACTION_FEATURE_WILL_UPLOAD" /* FEATURE_WILL_UPLOAD */, "true");
+    this.export("CODEQL_ACTION_VERSION" /* VERSION */, version);
+  }
   /** Gets a value indicating whether `set` was called at least once. */
   hasChanged() {
     return this.changed;
@@ -169892,13 +169903,6 @@ var ExhaustivityCheckingError = class extends Error {
 function assertNever(value) {
   throw new ExhaustivityCheckingError(value);
 }
-function initializeEnvironment(version, env = getEnv()) {
-  env.export("CODEQL_ACTION_FEATURE_MULTI_LANGUAGE" /* FEATURE_MULTI_LANGUAGE */, "false");
-  env.export("CODEQL_ACTION_FEATURE_SANDWICH" /* FEATURE_SANDWICH */, "false");
-  env.export("CODEQL_ACTION_FEATURE_SARIF_COMBINE" /* FEATURE_SARIF_COMBINE */, "true");
-  env.export("CODEQL_ACTION_FEATURE_WILL_UPLOAD" /* FEATURE_WILL_UPLOAD */, "true");
-  env.export("CODEQL_ACTION_VERSION" /* VERSION */, version);
-}
 function getBaseDatabaseOidsFilePath(config) {
   return path.join(config.dbLocation, BASE_DATABASE_OIDS_FILE_NAME);
 }
@@ -180759,7 +180763,7 @@ async function run(action) {
   let dependencyCacheResults;
   let databaseUploadResults = [];
   try {
-    initializeEnvironment(getActionVersion());
+    action.env.initialise(getActionVersion());
     persistInputs();
     const statusReportBase = await createStatusReportBase(
       "finish" /* Analyze */,
@@ -185938,8 +185942,8 @@ async function runWrapper2() {
 
 // src/autobuild-action.ts
 var core17 = __toESM(require_core());
-async function sendCompletedStatusReport(config, logger2, startedAt, allLanguages, failingLanguage, cause) {
-  initializeEnvironment(getActionVersion());
+async function sendCompletedStatusReport(env, config, logger2, startedAt, allLanguages, failingLanguage, cause) {
+  env.initialise(getActionVersion());
   const status = getActionsStatus(cause, failingLanguage);
   const statusReportBase = await createStatusReportBase(
     "autobuild" /* Autobuild */,
@@ -186011,6 +186015,7 @@ async function run2({
       `We were unable to automatically build your code. Please replace the call to the autobuild action with your custom build steps. ${error3.message}`
     );
     await sendCompletedStatusReport(
+      env,
       config,
       logger2,
       startedAt,
@@ -186021,7 +186026,13 @@ async function run2({
     return;
   }
   env.export("CODEQL_ACTION_AUTOBUILD_DID_COMPLETE_SUCCESSFULLY" /* AUTOBUILD_DID_COMPLETE_SUCCESSFULLY */, "true");
-  await sendCompletedStatusReport(config, logger2, startedAt, languages ?? []);
+  await sendCompletedStatusReport(
+    env,
+    config,
+    logger2,
+    startedAt,
+    languages ?? []
+  );
 }
 var autobuild = {
   name: "autobuild" /* Autobuild */,
@@ -186449,7 +186460,7 @@ async function run3(actionState) {
   let toolsSource;
   let toolsVersion;
   try {
-    initializeEnvironment(getActionVersion());
+    actionState.env.initialise(getActionVersion());
     persistInputs();
     apiDetails = {
       auth: getRequiredInput("token"),
@@ -187492,7 +187503,7 @@ async function run6(actionState) {
   let toolsSource;
   let toolsVersion;
   try {
-    initializeEnvironment(getActionVersion());
+    actionState.env.initialise(getActionVersion());
     const apiDetails = {
       auth: getRequiredInput("token"),
       externalRepoAuth: getOptionalInput("external-repository-token"),
@@ -188444,9 +188455,10 @@ async function sendSuccessStatusReport2(startedAt, uploadStats, logger2) {
     await sendStatusReport(statusReport);
   }
 }
-async function run8({ startedAt, logger: logger2 }) {
+async function run8(action) {
+  const logger2 = action.logger;
   try {
-    initializeEnvironment(getActionVersion());
+    action.env.initialise(getActionVersion());
     const gitHubVersion = await getGitHubVersion();
     checkActionVersion(getActionVersion(), gitHubVersion);
     persistInputs();
@@ -188460,7 +188472,7 @@ async function run8({ startedAt, logger: logger2 }) {
     const startingStatusReportBase = await createStatusReportBase(
       "upload-sarif" /* UploadSarif */,
       "starting",
-      startedAt,
+      action.startedAt,
       void 0,
       await checkDiskUsage(logger2),
       logger2
@@ -188503,7 +188515,7 @@ async function run8({ startedAt, logger: logger2 }) {
       }
     }
     await sendSuccessStatusReport2(
-      startedAt,
+      action.startedAt,
       codeScanningResult?.statusReport || {},
       logger2
     );
@@ -188514,7 +188526,7 @@ async function run8({ startedAt, logger: logger2 }) {
     const errorStatusReportBase = await createStatusReportBase(
       "upload-sarif" /* UploadSarif */,
       getActionsStatus(error3),
-      startedAt,
+      action.startedAt,
       void 0,
       await checkDiskUsage(logger2),
       logger2,
diff --git a/src/actions-util.test.ts b/src/actions-util.test.ts
index 17cf96a4a..8ef947cdc 100644
--- a/src/actions-util.test.ts
+++ b/src/actions-util.test.ts
@@ -12,8 +12,8 @@ import {
 import { computeAutomationID } from "./api-client";
 import { EnvVar } from "./environment";
 import { getRunnerLogger } from "./logging";
-import { RecordingLogger, setupTests } from "./testing-utils";
-import { initializeEnvironment, withTmpDir } from "./util";
+import { getTestEnv, RecordingLogger, setupTests } from "./testing-utils";
+import { withTmpDir } from "./util";
 
 setupTests(test);
 
@@ -228,8 +228,9 @@ test.serial(
 );
 
 test.serial("initializeEnvironment", (t) => {
-  initializeEnvironment("1.2.3");
-  t.deepEqual(process.env[EnvVar.VERSION], "1.2.3");
+  const env = getTestEnv();
+  env.initialise("1.2.3");
+  t.deepEqual(env.getOptional(EnvVar.VERSION), "1.2.3");
 });
 
 test.serial("fixCodeQualityCategory", (t) => {
diff --git a/src/analyze-action.ts b/src/analyze-action.ts
index 9efbb529b..f7cad45f3 100644
--- a/src/analyze-action.ts
+++ b/src/analyze-action.ts
@@ -238,7 +238,7 @@ async function run(action: ActionState<["Base", "Logger", "Env", "Actions"]>) {
   let databaseUploadResults: DatabaseUploadResult[] = [];
 
   try {
-    util.initializeEnvironment(actionsUtil.getActionVersion());
+    action.env.initialise(actionsUtil.getActionVersion());
 
     // Make inputs accessible in the `post` step, details at
     // https://github.com/github/codeql-action/issues/2553
diff --git a/src/api-client.test.ts b/src/api-client.test.ts
index 2bb878f3b..34ebd52e9 100644
--- a/src/api-client.test.ts
+++ b/src/api-client.test.ts
@@ -7,7 +7,7 @@ import { ProxyAgent } from "undici";
 import * as actionsUtil from "./actions-util";
 import * as api from "./api-client";
 import { DO_NOT_RETRY_STATUSES } from "./api-client";
-import { ActionsEnvVars, RegistryProxyVars } from "./environment";
+import { ActionsEnvVars, RegistryProxyVars, getEnv } from "./environment";
 import { GITHUB_DOTCOM_API_URL, GITHUB_DOTCOM_URL } from "./github";
 import {
   callee,
@@ -21,7 +21,7 @@ import * as util from "./util";
 setupTests(test);
 
 test.beforeEach(() => {
-  util.initializeEnvironment(actionsUtil.getActionVersion());
+  getEnv().initialise(actionsUtil.getActionVersion());
 });
 
 test.serial("getApiClient", async (t) => {
diff --git a/src/autobuild-action.ts b/src/autobuild-action.ts
index 18aad1185..3e2eb1a3f 100644
--- a/src/autobuild-action.ts
+++ b/src/autobuild-action.ts
@@ -10,7 +10,7 @@ import { getGitHubVersion } from "./api-client";
 import { determineAutobuildLanguages, runAutobuild } from "./autobuild";
 import { getCodeQL } from "./codeql";
 import { Config, getConfig } from "./config-utils";
-import { EnvVar } from "./environment";
+import { EnvVar, type Env } from "./environment";
 import { Language } from "./languages";
 import { Logger } from "./logging";
 import {
@@ -26,7 +26,6 @@ import {
   checkDiskUsage,
   checkGitHubVersionInRange,
   ConfigurationError,
-  initializeEnvironment,
   wrapError,
 } from "./util";
 
@@ -38,6 +37,7 @@ interface AutobuildStatusReport extends StatusReportBase {
 }
 
 async function sendCompletedStatusReport(
+  env: Env,
   config: Config | undefined,
   logger: Logger,
   startedAt: Date,
@@ -45,7 +45,7 @@ async function sendCompletedStatusReport(
   failingLanguage?: string,
   cause?: Error,
 ) {
-  initializeEnvironment(getActionVersion());
+  env.initialise(getActionVersion());
 
   const status = getActionsStatus(cause, failingLanguage);
   const statusReportBase = await createStatusReportBase(
@@ -129,6 +129,7 @@ async function run({
       `We were unable to automatically build your code. Please replace the call to the autobuild action with your custom build steps. ${error.message}`,
     );
     await sendCompletedStatusReport(
+      env,
       config,
       logger,
       startedAt,
@@ -141,7 +142,13 @@ async function run({
 
   env.export(EnvVar.AUTOBUILD_DID_COMPLETE_SUCCESSFULLY, "true");
 
-  await sendCompletedStatusReport(config, logger, startedAt, languages ?? []);
+  await sendCompletedStatusReport(
+    env,
+    config,
+    logger,
+    startedAt,
+    languages ?? [],
+  );
 }
 
 /** Defines the `autobuild` Action. */
diff --git a/src/codeql.test.ts b/src/codeql.test.ts
index e70dcd99f..e07d1b811 100644
--- a/src/codeql.test.ts
+++ b/src/codeql.test.ts
@@ -21,6 +21,7 @@ import {
 import type { Config } from "./config-utils";
 import * as defaults from "./defaults.json";
 import { DocUrl } from "./doc-url";
+import { getEnv } from "./environment";
 import { BuiltInLanguage } from "./languages";
 import { getRunnerLogger } from "./logging";
 import { ToolsSource } from "./setup-codeql";
@@ -37,14 +38,13 @@ import {
 } from "./testing-utils";
 import { ToolsDownloadStatusReport } from "./tools-download";
 import * as util from "./util";
-import { initializeEnvironment } from "./util";
 
 setupTests(test);
 
 let stubConfig: Config;
 
 test.beforeEach(() => {
-  initializeEnvironment("1.2.3");
+  getEnv().initialise("1.2.3");
 
   stubConfig = createTestConfig({
     languages: [BuiltInLanguage.cpp],
diff --git a/src/database-upload.test.ts b/src/database-upload.test.ts
index 908994112..7d7145dd3 100644
--- a/src/database-upload.test.ts
+++ b/src/database-upload.test.ts
@@ -15,6 +15,7 @@ import {
   cleanupAndUploadDatabases,
   uploadBundledDatabase,
 } from "./database-upload";
+import { getEnv } from "./environment";
 import { Feature } from "./feature-flags";
 import * as gitUtils from "./git-utils";
 import { BuiltInLanguage } from "./languages";
@@ -31,18 +32,12 @@ import {
   setupActionsVars,
   setupTests,
 } from "./testing-utils";
-import {
-  CleanupLevel,
-  GitHubVariant,
-  HTTPError,
-  initializeEnvironment,
-  withTmpDir,
-} from "./util";
+import { CleanupLevel, GitHubVariant, HTTPError, withTmpDir } from "./util";
 
 setupTests(test);
 
 test.beforeEach(() => {
-  initializeEnvironment("1.2.3");
+  getEnv().initialise("1.2.3");
 });
 
 const testRepoName: RepositoryNwo = { owner: "github", repo: "example" };
diff --git a/src/environment.ts b/src/environment.ts
index bbb29aab1..cff462fa3 100644
--- a/src/environment.ts
+++ b/src/environment.ts
@@ -371,6 +371,18 @@ export class Env extends ReadOnlyEnv {
     }
   }
 
+  /**
+   * Set some initial environment variables that we can set even without
+   * knowing what version of CodeQL we're running.
+   */
+  public initialise(version: string) {
+    this.export(EnvVar.FEATURE_MULTI_LANGUAGE, "false");
+    this.export(EnvVar.FEATURE_SANDWICH, "false");
+    this.export(EnvVar.FEATURE_SARIF_COMBINE, "true");
+    this.export(EnvVar.FEATURE_WILL_UPLOAD, "true");
+    this.export(EnvVar.VERSION, version);
+  }
+
   /** Gets a value indicating whether `set` was called at least once. */
   public hasChanged(): boolean {
     return this.changed;
diff --git a/src/feature-flags.test.ts b/src/feature-flags.test.ts
index d8b5eea04..7b1c1ef3e 100644
--- a/src/feature-flags.test.ts
+++ b/src/feature-flags.test.ts
@@ -4,6 +4,7 @@ import * as path from "path";
 import test from "ava";
 
 import * as defaults from "./defaults.json";
+import { getEnv } from "./environment";
 import {
   Feature,
   featureConfig,
@@ -26,12 +27,12 @@ import {
   setupTests,
   stubFeatureFlagApiEndpoint,
 } from "./testing-utils";
-import { GitHubVariant, initializeEnvironment, withTmpDir } from "./util";
+import { GitHubVariant, withTmpDir } from "./util";
 
 setupTests(test);
 
 test.beforeEach(() => {
-  initializeEnvironment("1.2.3");
+  getEnv().initialise("1.2.3");
 });
 
 test.serial(
diff --git a/src/feature-flags/offline-features.test.ts b/src/feature-flags/offline-features.test.ts
index 2870ef3b8..1c3d2a8c1 100644
--- a/src/feature-flags/offline-features.test.ts
+++ b/src/feature-flags/offline-features.test.ts
@@ -8,7 +8,7 @@ import {
   LoggedMessage,
   setupTests,
 } from "../testing-utils";
-import { GitHubVariant, initializeEnvironment, withTmpDir } from "../util";
+import { getEnv, GitHubVariant, withTmpDir } from "../util";
 
 import {
   assertAllFeaturesHaveDefaultValues,
@@ -18,7 +18,7 @@ import {
 setupTests(test);
 
 test.beforeEach(() => {
-  initializeEnvironment("1.2.3");
+  getEnv().initialise("1.2.3");
 });
 
 test("OfflineFeatures makes no API requests", async (t) => {
diff --git a/src/init-action.ts b/src/init-action.ts
index 7f9178304..b5749e9c8 100644
--- a/src/init-action.ts
+++ b/src/init-action.ts
@@ -92,7 +92,6 @@ import {
   DEFAULT_DEBUG_DATABASE_NAME,
   getCodeQLMemoryLimit,
   getThreadsFlagValue,
-  initializeEnvironment,
   ConfigurationError,
   wrapError,
   checkActionVersion,
@@ -225,7 +224,7 @@ async function run(
   let toolsVersion: string;
 
   try {
-    initializeEnvironment(getActionVersion());
+    actionState.env.initialise(getActionVersion());
 
     // Make inputs accessible in the `post` step.
     persistInputs();
diff --git a/src/setup-codeql-action.ts b/src/setup-codeql-action.ts
index 757b26fac..1bbfdacec 100644
--- a/src/setup-codeql-action.ts
+++ b/src/setup-codeql-action.ts
@@ -38,7 +38,6 @@ import {
   checkDiskUsage,
   checkForTimeout,
   checkGitHubVersionInRange,
-  initializeEnvironment,
   ConfigurationError,
   wrapError,
   checkActionVersion,
@@ -108,7 +107,7 @@ async function run(
   let toolsVersion: string;
 
   try {
-    initializeEnvironment(getActionVersion());
+    actionState.env.initialise(getActionVersion());
 
     const apiDetails = {
       auth: getRequiredInput("token"),
diff --git a/src/setup-codeql.test.ts b/src/setup-codeql.test.ts
index 7dfac1914..319729acd 100644
--- a/src/setup-codeql.test.ts
+++ b/src/setup-codeql.test.ts
@@ -11,7 +11,13 @@ import * as sinon from "sinon";
 import * as actionsUtil from "./actions-util";
 import * as api from "./api-client";
 import * as diagnostics from "./diagnostics";
-import { ActionsEnvVars, Env, EnvVar, ReadOnlyEnv } from "./environment";
+import {
+  ActionsEnvVars,
+  Env,
+  EnvVar,
+  getEnv,
+  ReadOnlyEnv,
+} from "./environment";
 import { Feature } from "./feature-flags";
 import { BuiltInLanguage } from "./languages";
 import { getRunnerLogger } from "./logging";
@@ -37,18 +43,12 @@ import {
   setupTests,
 } from "./testing-utils";
 import * as toolsDownload from "./tools-download";
-import {
-  getErrorMessage,
-  GitHubVariant,
-  HTTPError,
-  initializeEnvironment,
-  withTmpDir,
-} from "./util";
+import { getErrorMessage, GitHubVariant, HTTPError, withTmpDir } from "./util";
 
 setupTests(test);
 
 test.beforeEach(() => {
-  initializeEnvironment("1.2.3");
+  getEnv().initialise("1.2.3");
 });
 
 function stubDownloadAndExtract() {
diff --git a/src/setup/repository.test.ts b/src/setup/repository.test.ts
index d1c6d034c..9fabd8488 100644
--- a/src/setup/repository.test.ts
+++ b/src/setup/repository.test.ts
@@ -6,7 +6,6 @@ import * as sinon from "sinon";
 import * as actionsUtil from "../actions-util";
 import { ActionsEnvVars } from "../environment";
 import { callee, getTestEnv, setupTests } from "../testing-utils";
-import { initializeEnvironment } from "../util";
 
 import { getCodeQLActionRepository } from "./repository";
 
@@ -16,7 +15,7 @@ test.serial("getCodeQLActionRepository", async (t) => {
   const initialEnv = getTestEnv({
     [ActionsEnvVars.RUNNER_TEMP]: path.dirname(__dirname),
   });
-  initializeEnvironment("1.2.3", initialEnv);
+  initialEnv.initialise("1.2.3");
 
   const target = callee(getCodeQLActionRepository)
     .withArgs()
diff --git a/src/upload-lib.test.ts b/src/upload-lib.test.ts
index 2c27d56c1..393e3720d 100644
--- a/src/upload-lib.test.ts
+++ b/src/upload-lib.test.ts
@@ -10,17 +10,18 @@ import * as analyses from "./analyses";
 import { AnalysisKind, CodeQuality, CodeScanning } from "./analyses";
 import * as api from "./api-client";
 import * as diffUtils from "./diff-informed-analysis-utils";
+import { getEnv } from "./environment";
 import { getRunnerLogger, Logger } from "./logging";
 import * as sarif from "./sarif";
 import { setupTests } from "./testing-utils";
 import * as uploadLib from "./upload-lib";
 import { UploadPayload } from "./upload-lib/types";
-import { GitHubVariant, initializeEnvironment, withTmpDir } from "./util";
+import { GitHubVariant, withTmpDir } from "./util";
 
 setupTests(test);
 
 test.beforeEach(() => {
-  initializeEnvironment("1.2.3");
+  getEnv().initialise("1.2.3");
 });
 
 test.serial("validateSarifFileSchema - valid", (t) => {
diff --git a/src/upload-sarif-action.ts b/src/upload-sarif-action.ts
index d3437510c..7d67c5567 100644
--- a/src/upload-sarif-action.ts
+++ b/src/upload-sarif-action.ts
@@ -23,7 +23,6 @@ import {
   ConfigurationError,
   checkActionVersion,
   checkDiskUsage,
-  initializeEnvironment,
   shouldSkipSarifUpload,
   wrapError,
 } from "./util";
@@ -54,11 +53,13 @@ async function sendSuccessStatusReport(
   }
 }
 
-async function run({ startedAt, logger }: ActionState<["Base", "Logger"]>) {
+async function run(action: ActionState<["Base", "Env", "Logger"]>) {
   // To capture errors appropriately, keep as much code within the try-catch as
   // possible, and only use safe functions outside.
+  const logger = action.logger;
+
   try {
-    initializeEnvironment(getActionVersion());
+    action.env.initialise(getActionVersion());
 
     const gitHubVersion = await getGitHubVersion();
     checkActionVersion(getActionVersion(), gitHubVersion);
@@ -77,7 +78,7 @@ async function run({ startedAt, logger }: ActionState<["Base", "Logger"]>) {
     const startingStatusReportBase = await createStatusReportBase(
       ActionName.UploadSarif,
       "starting",
-      startedAt,
+      action.startedAt,
       undefined,
       await checkDiskUsage(logger),
       logger,
@@ -131,7 +132,7 @@ async function run({ startedAt, logger }: ActionState<["Base", "Logger"]>) {
       // so we can't wait for that here.
     }
     await sendSuccessStatusReport(
-      startedAt,
+      action.startedAt,
       codeScanningResult?.statusReport || {},
       logger,
     );
@@ -147,7 +148,7 @@ async function run({ startedAt, logger }: ActionState<["Base", "Logger"]>) {
     const errorStatusReportBase = await createStatusReportBase(
       ActionName.UploadSarif,
       getActionsStatus(error),
-      startedAt,
+      action.startedAt,
       undefined,
       await checkDiskUsage(logger),
       logger,
diff --git a/src/util.ts b/src/util.ts
index 7ba59c675..b9f51011e 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -20,8 +20,6 @@ import {
   getRequiredEnvParam,
   isInTestMode,
   exportEnvVar,
-  getEnv,
-  type Env,
 } from "./environment";
 import { ConfigurationError, getErrorMessage, wrapError } from "./errors";
 import { GitHubVariant, type GitHubVersion } from "./github";
@@ -538,18 +536,6 @@ export function assertNever(value: never): never {
   throw new ExhaustivityCheckingError(value);
 }
 
-/**
- * Set some initial environment variables that we can set even without
- * knowing what version of CodeQL we're running.
- */
-export function initializeEnvironment(version: string, env: Env = getEnv()) {
-  env.export(EnvVar.FEATURE_MULTI_LANGUAGE, "false");
-  env.export(EnvVar.FEATURE_SANDWICH, "false");
-  env.export(EnvVar.FEATURE_SARIF_COMBINE, "true");
-  env.export(EnvVar.FEATURE_WILL_UPLOAD, "true");
-  env.export(EnvVar.VERSION, version);
-}
-
 export function getBaseDatabaseOidsFilePath(
   config: ActionConfig<"dbLocation">,
 ): string {