diff --git a/README.md b/README.md
index 1faa1f6..acea710 100644
--- a/README.md
+++ b/README.md
@@ -92,11 +92,19 @@ You can control the output from Aikido Safe Chain using the `--safe-chain-loggin
 
 - `--safe-chain-logging=silent` - Suppresses all Aikido Safe Chain output except when malware is blocked. The package manager output is written to stdout as normal, and Safe Chain only writes a short message if it has blocked malware and causes the process to exit.
 
-Example usage:
+  Example usage:
 
-```shell
-npm install express --safe-chain-logging=silent
-```
+  ```shell
+  npm install express --safe-chain-logging=silent
+  ```
+
+- `--safe-chain-logging=verbose` - Enables detailed diagnostic output from Aikido Safe Chain. Useful for troubleshooting issues or understanding what Safe Chain is doing behind the scenes.
+
+  Example usage:
+
+  ```shell
+  npm install express --safe-chain-logging=verbose
+  ```
 
 # Usage in CI/CD
 
diff --git a/package.json b/package.json
index 0193a82..6a5dec3 100644
--- a/package.json
+++ b/package.json
@@ -9,7 +9,8 @@
   "scripts": {
     "test": "npm run test --workspace=packages/safe-chain --workspace=packages/safe-chain-bun",
     "test:e2e": "npm run test --workspace=test/e2e",
-    "lint": "npm run lint --workspace=packages/safe-chain"
+    "lint": "npm run lint --workspace=packages/safe-chain",
+    "typecheck": "npm run typecheck --workspace=packages/safe-chain"
   },
   "repository": {
     "type": "git",
diff --git a/packages/safe-chain/bin/aikido-bun.js b/packages/safe-chain/bin/aikido-bun.js
index d6751fc..c128445 100755
--- a/packages/safe-chain/bin/aikido-bun.js
+++ b/packages/safe-chain/bin/aikido-bun.js
@@ -9,5 +9,4 @@ const packageManagerName = "bun";
 initializePackageManager(packageManagerName);
 var exitCode = await main(process.argv.slice(2));
 
-// @ts-expect-error scanCommand can return an empty array in main
 process.exit(exitCode);
diff --git a/packages/safe-chain/bin/aikido-bunx.js b/packages/safe-chain/bin/aikido-bunx.js
index 5ec9646..2e83793 100755
--- a/packages/safe-chain/bin/aikido-bunx.js
+++ b/packages/safe-chain/bin/aikido-bunx.js
@@ -9,5 +9,4 @@ const packageManagerName = "bunx";
 initializePackageManager(packageManagerName);
 var exitCode = await main(process.argv.slice(2));
 
-// @ts-expect-error scanCommand can return an empty array in main
 process.exit(exitCode);
diff --git a/packages/safe-chain/bin/aikido-npm.js b/packages/safe-chain/bin/aikido-npm.js
index 3e3ad0c..a50d9b5 100755
--- a/packages/safe-chain/bin/aikido-npm.js
+++ b/packages/safe-chain/bin/aikido-npm.js
@@ -9,5 +9,4 @@ const packageManagerName = "npm";
 initializePackageManager(packageManagerName);
 var exitCode = await main(process.argv.slice(2));
 
-// @ts-expect-error scanCommand can return an empty array in main
 process.exit(exitCode);
diff --git a/packages/safe-chain/bin/aikido-npx.js b/packages/safe-chain/bin/aikido-npx.js
index 20b970a..e1687d3 100755
--- a/packages/safe-chain/bin/aikido-npx.js
+++ b/packages/safe-chain/bin/aikido-npx.js
@@ -9,5 +9,4 @@ const packageManagerName = "npx";
 initializePackageManager(packageManagerName);
 var exitCode = await main(process.argv.slice(2));
 
-// @ts-expect-error scanCommand can return an empty array in main
 process.exit(exitCode);
diff --git a/packages/safe-chain/bin/aikido-pnpm.js b/packages/safe-chain/bin/aikido-pnpm.js
index 24ed8a9..cf5125e 100755
--- a/packages/safe-chain/bin/aikido-pnpm.js
+++ b/packages/safe-chain/bin/aikido-pnpm.js
@@ -9,5 +9,4 @@ const packageManagerName = "pnpm";
 initializePackageManager(packageManagerName);
 var exitCode = await main(process.argv.slice(2));
 
-// @ts-expect-error scanCommand can return an empty array in main
 process.exit(exitCode);
diff --git a/packages/safe-chain/bin/aikido-pnpx.js b/packages/safe-chain/bin/aikido-pnpx.js
index 70a5bba..6182810 100755
--- a/packages/safe-chain/bin/aikido-pnpx.js
+++ b/packages/safe-chain/bin/aikido-pnpx.js
@@ -9,5 +9,4 @@ const packageManagerName = "pnpx";
 initializePackageManager(packageManagerName);
 var exitCode = await main(process.argv.slice(2));
 
-// @ts-expect-error scanCommand can return an empty array in main
 process.exit(exitCode);
diff --git a/packages/safe-chain/bin/aikido-yarn.js b/packages/safe-chain/bin/aikido-yarn.js
index 834b503..eee14e8 100755
--- a/packages/safe-chain/bin/aikido-yarn.js
+++ b/packages/safe-chain/bin/aikido-yarn.js
@@ -9,5 +9,4 @@ const packageManagerName = "yarn";
 initializePackageManager(packageManagerName);
 var exitCode = await main(process.argv.slice(2));
 
-// @ts-expect-error scanCommand can return an empty array in main
 process.exit(exitCode);
diff --git a/packages/safe-chain/src/config/settings.js b/packages/safe-chain/src/config/settings.js
index d7ccf87..46cc30c 100644
--- a/packages/safe-chain/src/config/settings.js
+++ b/packages/safe-chain/src/config/settings.js
@@ -7,6 +7,10 @@ export function getLoggingLevel() {
     return LOGGING_SILENT;
   }
 
+  if (level === LOGGING_VERBOSE) {
+    return LOGGING_VERBOSE;
+  }
+
   return LOGGING_NORMAL;
 }
 
@@ -34,3 +38,4 @@ export function setEcoSystem(setting) {
 
 export const LOGGING_SILENT = "silent";
 export const LOGGING_NORMAL = "normal";
+export const LOGGING_VERBOSE = "verbose";
diff --git a/packages/safe-chain/src/environment/userInteraction.js b/packages/safe-chain/src/environment/userInteraction.js
index 3f690fb..3222874 100644
--- a/packages/safe-chain/src/environment/userInteraction.js
+++ b/packages/safe-chain/src/environment/userInteraction.js
@@ -2,12 +2,28 @@
 import chalk from "chalk";
 import ora from "ora";
 import { isCi } from "./environment.js";
-import { getLoggingLevel, LOGGING_SILENT } from "../config/settings.js";
+import {
+  getLoggingLevel,
+  LOGGING_SILENT,
+  LOGGING_VERBOSE,
+} from "../config/settings.js";
+
+/**
+ * @type {{ bufferOutput: boolean, bufferedMessages:(() => void)[]}}
+ */
+const state = {
+  bufferOutput: false,
+  bufferedMessages: [],
+};
 
 function isSilentMode() {
   return getLoggingLevel() === LOGGING_SILENT;
 }
 
+function isVerboseMode() {
+  return getLoggingLevel() === LOGGING_VERBOSE;
+}
+
 function emptyLine() {
   if (isSilentMode()) return;
 
@@ -22,7 +38,7 @@ function emptyLine() {
 function writeInformation(message, ...optionalParams) {
   if (isSilentMode()) return;
 
-  console.log(message, ...optionalParams);
+  writeOrBuffer(() => console.log(message, ...optionalParams));
 }
 
 /**
@@ -36,7 +52,7 @@ function writeWarning(message, ...optionalParams) {
   if (!isCi()) {
     message = chalk.yellow(message);
   }
-  console.warn(message, ...optionalParams);
+  writeOrBuffer(() => console.warn(message, ...optionalParams));
 }
 
 /**
@@ -48,7 +64,7 @@ function writeError(message, ...optionalParams) {
   if (!isCi()) {
     message = chalk.red(message);
   }
-  console.error(message, ...optionalParams);
+  writeOrBuffer(() => console.error(message, ...optionalParams));
 }
 
 function writeExitWithoutInstallingMaliciousPackages() {
@@ -56,7 +72,30 @@ function writeExitWithoutInstallingMaliciousPackages() {
   if (!isCi()) {
     message = chalk.red(message);
   }
-  console.error(message);
+  writeOrBuffer(() => console.error(message));
+}
+
+/**
+ * @param {string} message
+ * @param {...any} optionalParams
+ * @returns {void}
+ */
+function writeVerbose(message, ...optionalParams) {
+  if (!isVerboseMode()) return;
+
+  writeOrBuffer(() => console.log(message, ...optionalParams));
+}
+
+/**
+ *
+ * @param {() => void} messageFunction
+ */
+function writeOrBuffer(messageFunction) {
+  if (state.bufferOutput) {
+    state.bufferedMessages.push(messageFunction);
+  } else {
+    messageFunction();
+  }
 }
 
 /**
@@ -114,11 +153,27 @@ function startProcess(message) {
   }
 }
 
+function startBufferingLogs() {
+  state.bufferOutput = true;
+  state.bufferedMessages = [];
+}
+
+function writeBufferedLogsAndStopBuffering() {
+  state.bufferOutput = false;
+  for (const log of state.bufferedMessages) {
+    log();
+  }
+  state.bufferedMessages = [];
+}
+
 export const ui = {
+  writeVerbose,
   writeInformation,
   writeWarning,
   writeError,
   writeExitWithoutInstallingMaliciousPackages,
   emptyLine,
   startProcess,
+  startBufferingLogs,
+  writeBufferedLogsAndStopBuffering,
 };
diff --git a/packages/safe-chain/src/main.js b/packages/safe-chain/src/main.js
index fca1218..3fba24f 100644
--- a/packages/safe-chain/src/main.js
+++ b/packages/safe-chain/src/main.js
@@ -9,16 +9,18 @@ import chalk from "chalk";
 
 /**
  * @param {string[]} args
- * @returns {Promise<number | never[]>}
+ * @returns {Promise<number>}
  */
 export async function main(args) {
+  process.on("SIGINT", handleProcessTermination);
+  process.on("SIGTERM", handleProcessTermination);
+
   const proxy = createSafeChainProxy();
   await proxy.startServer();
 
   // Global error handlers to log unhandled errors
   process.on("uncaughtException", (error) => {
     ui.writeError(`Safe-chain: Uncaught exception: ${error.message}`);
-    // @ts-expect-error writeVerbose will be added in a future PR
     ui.writeVerbose(`Stack trace: ${error.stack}`);
     process.exit(1);
   });
@@ -26,7 +28,6 @@ export async function main(args) {
   process.on("unhandledRejection", (reason) => {
     ui.writeError(`Safe-chain: Unhandled promise rejection: ${reason}`);
     if (reason instanceof Error) {
-      // @ts-expect-error writeVerbose will be added in a future PR
       ui.writeVerbose(`Stack trace: ${reason.stack}`);
     }
     process.exit(1);
@@ -46,8 +47,16 @@ export async function main(args) {
       }
     }
 
+    // Buffer logs during package manager execution, this avoids interleaving
+    //  of logs from the package manager and safe-chain
+    // Not doing this could cause bugs to disappear when cursor movement codes
+    //  are written by the package manager while safe-chain is writing logs
+    ui.startBufferingLogs();
     const packageManagerResult = await getPackageManager().runCommand(args);
 
+    // Write all buffered logs
+    ui.writeBufferedLogsAndStopBuffering();
+
     if (!proxy.verifyNoMaliciousPackages()) {
       return 1;
     }
@@ -72,3 +81,7 @@ export async function main(args) {
     await proxy.stopServer();
   }
 }
+
+function handleProcessTermination() {
+  ui.writeBufferedLogsAndStopBuffering();
+}
diff --git a/packages/safe-chain/src/packagemanager/bun/createBunPackageManager.js b/packages/safe-chain/src/packagemanager/bun/createBunPackageManager.js
index 9716261..037a512 100644
--- a/packages/safe-chain/src/packagemanager/bun/createBunPackageManager.js
+++ b/packages/safe-chain/src/packagemanager/bun/createBunPackageManager.js
@@ -39,7 +39,6 @@ async function runBunCommand(command, args) {
   try {
     const result = await safeSpawn(command, args, {
       stdio: "inherit",
-      // @ts-expect-error values of process.env can be string | undefined
       env: mergeSafeChainProxyEnvironmentVariables(process.env),
     });
     return { status: result.status };
diff --git a/packages/safe-chain/src/packagemanager/npm/runNpmCommand.js b/packages/safe-chain/src/packagemanager/npm/runNpmCommand.js
index c068240..af57fad 100644
--- a/packages/safe-chain/src/packagemanager/npm/runNpmCommand.js
+++ b/packages/safe-chain/src/packagemanager/npm/runNpmCommand.js
@@ -11,7 +11,6 @@ export async function runNpm(args) {
   try {
     const result = await safeSpawn("npm", args, {
       stdio: "inherit",
-      // @ts-expect-error values of process.env can be string | undefined
       env: mergeSafeChainProxyEnvironmentVariables(process.env),
     });
     return { status: result.status };
@@ -24,37 +23,3 @@ export async function runNpm(args) {
     }
   }
 }
-
-/**
- * @param {string[]} args
- * @returns {Promise<{status: number, output?: string}>}
- */
-export async function dryRunNpmCommandAndOutput(args) {
-  try {
-    const result = await safeSpawn(
-      "npm",
-      [...args, "--ignore-scripts", "--dry-run"],
-      {
-        stdio: "pipe",
-        // @ts-expect-error values of process.env can be string | undefined
-        env: mergeSafeChainProxyEnvironmentVariables(process.env),
-      }
-    );
-    return {
-      status: result.status,
-      output: result.status === 0 ? result.stdout : result.stderr,
-    };
-  } catch (/** @type any */ error) {
-    if (error.status) {
-      const output =
-        error.stdout?.toString() ??
-        error.stderr?.toString() ??
-        error.message ??
-        "";
-      return { status: error.status, output };
-    } else {
-      ui.writeError("Error executing command:", error.message);
-      return { status: 1 };
-    }
-  }
-}
diff --git a/packages/safe-chain/src/packagemanager/npx/runNpxCommand.js b/packages/safe-chain/src/packagemanager/npx/runNpxCommand.js
index 61adcaa..2501b79 100644
--- a/packages/safe-chain/src/packagemanager/npx/runNpxCommand.js
+++ b/packages/safe-chain/src/packagemanager/npx/runNpxCommand.js
@@ -11,7 +11,6 @@ export async function runNpx(args) {
   try {
     const result = await safeSpawn("npx", args, {
       stdio: "inherit",
-      // @ts-expect-error values of process.env can be string | undefined
       env: mergeSafeChainProxyEnvironmentVariables(process.env),
     });
     return { status: result.status };
diff --git a/packages/safe-chain/src/packagemanager/pnpm/runPnpmCommand.js b/packages/safe-chain/src/packagemanager/pnpm/runPnpmCommand.js
index db4ffa9..d958fb8 100644
--- a/packages/safe-chain/src/packagemanager/pnpm/runPnpmCommand.js
+++ b/packages/safe-chain/src/packagemanager/pnpm/runPnpmCommand.js
@@ -13,13 +13,11 @@ export async function runPnpmCommand(args, toolName = "pnpm") {
     if (toolName === "pnpm") {
       result = await safeSpawn("pnpm", args, {
         stdio: "inherit",
-        // @ts-expect-error values of process.env can be string | undefined
         env: mergeSafeChainProxyEnvironmentVariables(process.env),
       });
     } else if (toolName === "pnpx") {
       result = await safeSpawn("pnpx", args, {
         stdio: "inherit",
-        // @ts-expect-error values of process.env can be string | undefined
         env: mergeSafeChainProxyEnvironmentVariables(process.env),
       });
     } else {
diff --git a/packages/safe-chain/src/packagemanager/yarn/runYarnCommand.js b/packages/safe-chain/src/packagemanager/yarn/runYarnCommand.js
index 1ba0f5c..2089551 100644
--- a/packages/safe-chain/src/packagemanager/yarn/runYarnCommand.js
+++ b/packages/safe-chain/src/packagemanager/yarn/runYarnCommand.js
@@ -9,7 +9,6 @@ import { mergeSafeChainProxyEnvironmentVariables } from "../../registryProxy/reg
  */
 export async function runYarnCommand(args) {
   try {
-    // @ts-expect-error values of process.env can be string | undefined
     const env = mergeSafeChainProxyEnvironmentVariables(process.env);
     await fixYarnProxyEnvironmentVariables(env);
 
@@ -36,29 +35,7 @@ export async function runYarnCommand(args) {
 async function fixYarnProxyEnvironmentVariables(env) {
   // Yarn ignores standard proxy environment variable HTTPS_PROXY
   // It does respect NODE_EXTRA_CA_CERTS for custom CA certificates though.
-  // Don't use YARN_HTTPS_CA_FILE_PATH though, as it causes to ignore all system CAs
+  // Don't use YARN_HTTPS_CA_FILE_PATH or YARN_CA_FILE_PATH though, it causes yarn to ignore all system CAs
 
-  // Yarn v2/v3 and v4+ use different environment variables for proxy and CA certs
-  // When setting all variables, yarn returns an error about conflicting variables
-  //  - v2/v3: "Usage Error: Unrecognized or legacy configuration settings found: httpsCaFilePath"
-  //  - v4+:   "Usage Error: Unrecognized or legacy configuration settings found: caFilePath"
-
-  const version = await yarnVersion();
-  const majorVersion = parseInt(version.split(".")[0]);
-
-  if (majorVersion >= 4) {
-    env.YARN_HTTPS_PROXY = env.HTTPS_PROXY;
-  } else if (majorVersion === 2 || majorVersion === 3) {
-    env.YARN_HTTPS_PROXY = env.HTTPS_PROXY;
-  }
-}
-
-async function yarnVersion() {
-  const result = await safeSpawn("yarn", ["--version"], {
-    stdio: "pipe",
-  });
-  if (result.status !== 0) {
-    throw new Error("Failed to get yarn version");
-  }
-  return result.stdout.trim();
+  env.YARN_HTTPS_PROXY = env.HTTPS_PROXY;
 }
diff --git a/packages/safe-chain/src/packagemanager/yarn/runYarnCommand.spec.js b/packages/safe-chain/src/packagemanager/yarn/runYarnCommand.spec.js
index bd3d04d..21475f9 100644
--- a/packages/safe-chain/src/packagemanager/yarn/runYarnCommand.spec.js
+++ b/packages/safe-chain/src/packagemanager/yarn/runYarnCommand.spec.js
@@ -103,13 +103,13 @@ describe("runYarnCommand", () => {
     );
   });
 
-  it("should not set Yarn-specific proxy vars for Yarn v1", async () => {
+  it("should set YARN_HTTPS_PROXY for Yarn v1", async () => {
     yarnVersion = "1.22.19";
     await runYarnCommand(["add", "lodash"]);
 
     assert.strictEqual(
       capturedEnv.YARN_HTTPS_PROXY,
-      undefined,
+      "http://localhost:8080",
       "YARN_HTTPS_PROXY should not be set for Yarn v1"
     );
     assert.strictEqual(
diff --git a/packages/safe-chain/src/registryProxy/mitmRequestHandler.js b/packages/safe-chain/src/registryProxy/mitmRequestHandler.js
index 5bbf38a..6f7b20e 100644
--- a/packages/safe-chain/src/registryProxy/mitmRequestHandler.js
+++ b/packages/safe-chain/src/registryProxy/mitmRequestHandler.js
@@ -5,13 +5,17 @@ import { ui } from "../environment/userInteraction.js";
 
 /**
  * @param {import("http").IncomingMessage} req
- * @param {import("net").Socket} clientSocket
+ * @param {import("http").ServerResponse} clientSocket
  * @param {(target: string) => Promise<boolean>} isAllowed
  */
 export function mitmConnect(req, clientSocket, isAllowed) {
+  ui.writeVerbose(`Safe-chain: Set up MITM tunnel for ${req.url}`);
   const { hostname } = new URL(`http://${req.url}`);
 
-  clientSocket.on("error", () => {
+  clientSocket.on("error", (err) => {
+    ui.writeVerbose(
+      `Safe-chain: Client socket error for ${req.url}: ${err.message}`
+    );
     // NO-OP
     // This can happen if the client TCP socket sends RST instead of FIN.
     // Not subscribing to 'close' event will cause node to throw and crash.
@@ -21,7 +25,6 @@ export function mitmConnect(req, clientSocket, isAllowed) {
 
   server.on("error", (err) => {
     ui.writeError(`Safe-chain: HTTPS server error: ${err.message}`);
-    // @ts-expect-error Property 'headersSent' does not exist on type 'Socket'
     if (!clientSocket.headersSent) {
       clientSocket.end("HTTP/1.1 502 Bad Gateway\r\n\r\n");
     } else if (clientSocket.writable) {
@@ -51,11 +54,18 @@ function createHttpsServer(hostname, isAllowed) {
    * @returns {Promise<void>}
    */
   async function handleRequest(req, res) {
-    // @ts-expect-error req.url might be undefined
+    if (!req.url) {
+      ui.writeError("Safe-chain: Request missing URL");
+      res.writeHead(400, "Bad Request");
+      res.end("Bad Request: Missing URL");
+      return;
+    }
+
     const pathAndQuery = getRequestPathAndQuery(req.url);
     const targetUrl = `https://${hostname}${pathAndQuery}`;
 
     if (!(await isAllowed(targetUrl))) {
+      ui.writeVerbose(`Safe-chain: Blocking request to ${targetUrl}`);
       res.writeHead(403, "Forbidden - blocked by safe-chain");
       res.end("Blocked by safe-chain");
       return;
@@ -96,7 +106,10 @@ function getRequestPathAndQuery(url) {
 function forwardRequest(req, hostname, res) {
   const proxyReq = createProxyRequest(hostname, req, res);
 
-  proxyReq.on("error", () => {
+  proxyReq.on("error", (err) => {
+    ui.writeVerbose(
+      `Safe-chain: Error occurred while proxying request: ${err.message}`
+    );
     res.writeHead(502);
     res.end("Bad Gateway");
   });
@@ -111,6 +124,9 @@ function forwardRequest(req, hostname, res) {
   });
 
   req.on("end", () => {
+    ui.writeVerbose(
+      `Safe-chain: Finished proxying request to ${req.url} for ${hostname}`
+    );
     proxyReq.end();
   });
 }
@@ -152,7 +168,13 @@ function createProxyRequest(hostname, req, res) {
       }
     });
 
-    // @ts-expect-error statusCode might be undefined
+    if (!proxyRes.statusCode) {
+      ui.writeError("Safe-chain: Proxy response missing status code");
+      res.writeHead(500);
+      res.end("Internal Server Error");
+      return;
+    }
+
     res.writeHead(proxyRes.statusCode, proxyRes.headers);
     proxyRes.pipe(res);
   });
diff --git a/packages/safe-chain/src/registryProxy/plainHttpProxy.js b/packages/safe-chain/src/registryProxy/plainHttpProxy.js
index 16b305a..75b9d77 100644
--- a/packages/safe-chain/src/registryProxy/plainHttpProxy.js
+++ b/packages/safe-chain/src/registryProxy/plainHttpProxy.js
@@ -1,5 +1,6 @@
 import * as http from "http";
 import * as https from "https";
+import { ui } from "../environment/userInteraction.js";
 
 /**
  * @param {import("http").IncomingMessage} req
@@ -8,7 +9,13 @@ import * as https from "https";
  * @returns {void}
  */
 export function handleHttpProxyRequest(req, res) {
-  // @ts-expect-error req.url might be undefined
+  if (!req.url) {
+    ui.writeError("Safe-chain: Request missing URL");
+    res.writeHead(400, "Bad Request");
+    res.end("Bad Request: Missing URL");
+    return;
+  }
+
   const url = new URL(req.url);
 
   // The protocol for the plainHttpProxy should usually only be http:
@@ -27,11 +34,16 @@ export function handleHttpProxyRequest(req, res) {
 
   const proxyRequest = protocol
     .request(
-      // @ts-expect-error req.url might be undefined
       req.url,
       { method: req.method, headers: req.headers },
       (proxyRes) => {
-        // @ts-expect-error statusCode might be undefined
+        if (!proxyRes.statusCode) {
+          ui.writeError("Safe-chain: Proxy response missing status code");
+          res.writeHead(500);
+          res.end("Internal Server Error");
+          return;
+        }
+
         res.writeHead(proxyRes.statusCode, proxyRes.headers);
         proxyRes.pipe(res);
 
diff --git a/packages/safe-chain/src/registryProxy/registryProxy.js b/packages/safe-chain/src/registryProxy/registryProxy.js
index 99faa87..c5e272b 100644
--- a/packages/safe-chain/src/registryProxy/registryProxy.js
+++ b/packages/safe-chain/src/registryProxy/registryProxy.js
@@ -44,7 +44,7 @@ function getSafeChainProxyEnvironmentVariables() {
 }
 
 /**
- * @param {Record<string, string>} env
+ * @param {Record<string, string | undefined>} env
  *
  * @returns {Record<string, string>}
  */
@@ -57,7 +57,7 @@ export function mergeSafeChainProxyEnvironmentVariables(env) {
     // So we only copy the variable if it's not already set in a different case
     const upperKey = key.toUpperCase();
 
-    if (!proxyEnv[upperKey]) {
+    if (!proxyEnv[upperKey] && env[key]) {
       proxyEnv[key] = env[key];
     }
   }
@@ -123,7 +123,7 @@ function stopServer(server) {
 
 /**
  * @param {import("http").IncomingMessage} req
- * @param {import("net").Socket} clientSocket
+ * @param {import("http").ServerResponse} clientSocket
  * @param {Buffer} head
  *
  * @returns {void}
@@ -146,6 +146,7 @@ function handleConnect(req, clientSocket, head) {
     mitmConnect(req, clientSocket, isAllowedUrl);
   } else {
     // For other hosts, just tunnel the request to the destination tcp socket
+    ui.writeVerbose(`Safe-chain: Tunneling request to ${req.url}`);
     tunnelRequest(req, clientSocket, head);
   }
 }
diff --git a/packages/safe-chain/src/registryProxy/tunnelRequestHandler.js b/packages/safe-chain/src/registryProxy/tunnelRequestHandler.js
index 452ef15..4b756d7 100644
--- a/packages/safe-chain/src/registryProxy/tunnelRequestHandler.js
+++ b/packages/safe-chain/src/registryProxy/tunnelRequestHandler.js
@@ -3,7 +3,7 @@ import { ui } from "../environment/userInteraction.js";
 
 /**
  * @param {import("http").IncomingMessage} req
- * @param {import("net").Socket} clientSocket
+ * @param {import("http").ServerResponse} clientSocket
  * @param {Buffer} head
  *
  * @returns {void}
@@ -30,7 +30,7 @@ export function tunnelRequest(req, clientSocket, head) {
 
 /**
  * @param {import("http").IncomingMessage} req
- * @param {import("net").Socket} clientSocket
+ * @param {import("http").ServerResponse} clientSocket
  * @param {Buffer} head
  *
  * @returns {void}
@@ -38,13 +38,16 @@ export function tunnelRequest(req, clientSocket, head) {
 function tunnelRequestToDestination(req, clientSocket, head) {
   const { port, hostname } = new URL(`http://${req.url}`);
 
-  // @ts-expect-error port from URL is a string but net.connect accepts number
-  const serverSocket = net.connect(port || 443, hostname, () => {
-    clientSocket.write("HTTP/1.1 200 Connection Established\r\n\r\n");
-    serverSocket.write(head);
-    serverSocket.pipe(clientSocket);
-    clientSocket.pipe(serverSocket);
-  });
+  const serverSocket = net.connect(
+    Number.parseInt(port) || 443,
+    hostname,
+    () => {
+      clientSocket.write("HTTP/1.1 200 Connection Established\r\n\r\n");
+      serverSocket.write(head);
+      serverSocket.pipe(clientSocket);
+      clientSocket.pipe(serverSocket);
+    }
+  );
 
   clientSocket.on("error", () => {
     // This can happen if the client TCP socket sends RST instead of FIN.
@@ -66,7 +69,7 @@ function tunnelRequestToDestination(req, clientSocket, head) {
 
 /**
  * @param {import("http").IncomingMessage} req
- * @param {import("net").Socket} clientSocket
+ * @param {import("http").ServerResponse} clientSocket
  * @param {Buffer} head
  * @param {string} proxyUrl
  */
@@ -75,10 +78,9 @@ function tunnelRequestViaProxy(req, clientSocket, head, proxyUrl) {
   const proxy = new URL(proxyUrl);
 
   // Connect to proxy server
-  // @ts-expect-error net.connect wants port as number but proxy.port is string
   const proxySocket = net.connect({
     host: proxy.hostname,
-    port: proxy.port,
+    port: Number.parseInt(proxy.port) || 80,
   });
 
   proxySocket.on("connect", () => {
diff --git a/packages/safe-chain/src/scanning/audit/index.js b/packages/safe-chain/src/scanning/audit/index.js
index 1514eb8..2d215cb 100644
--- a/packages/safe-chain/src/scanning/audit/index.js
+++ b/packages/safe-chain/src/scanning/audit/index.js
@@ -1,3 +1,4 @@
+import { ui } from "../../environment/userInteraction.js";
 import {
   MALWARE_STATUS_MALWARE,
   openMalwareDatabase,
@@ -40,8 +41,14 @@ export async function auditChanges(changes) {
     );
 
     if (malwarePackage) {
+      ui.writeVerbose(
+        `Safe-chain: Package ${change.name}@${change.version} is marked as malware: ${malwarePackage.status}`
+      );
       disallowedChanges.push({ ...change, reason: malwarePackage.status });
     } else {
+      ui.writeVerbose(
+        `Safe-chain: Package ${change.name}@${change.version} is clean`
+      );
       allowedChanges.push(change);
     }
   }
diff --git a/packages/safe-chain/src/scanning/index.js b/packages/safe-chain/src/scanning/index.js
index d8e817e..44ff57c 100644
--- a/packages/safe-chain/src/scanning/index.js
+++ b/packages/safe-chain/src/scanning/index.js
@@ -21,11 +21,11 @@ export function shouldScanCommand(args) {
 /**
  * @param {string[]} args
  *
- * @returns {Promise<number | never[]>}
+ * @returns {Promise<number>}
  */
 export async function scanCommand(args) {
   if (!shouldScanCommand(args)) {
-    return [];
+    return 0;
   }
 
   let timedOut = false;
diff --git a/packages/safe-chain/src/scanning/malwareDatabase.js b/packages/safe-chain/src/scanning/malwareDatabase.js
index b11f8d8..4aba43c 100644
--- a/packages/safe-chain/src/scanning/malwareDatabase.js
+++ b/packages/safe-chain/src/scanning/malwareDatabase.js
@@ -91,10 +91,19 @@ async function getMalwareDatabase() {
     }
 
     const { malwareDatabase, version } = await fetchMalwareDatabase();
-    // @ts-expect-error version can be undefined
-    writeDatabaseToLocalCache(malwareDatabase, version);
 
-    return malwareDatabase;
+    if (version) {
+      // Only cache the malware database when we have a version.
+      writeDatabaseToLocalCache(malwareDatabase, version);
+      return malwareDatabase;
+    } else {
+      // We received a valid malware database, but the response
+      // did not contain an etag header with the version
+      ui.writeWarning(
+        "The malware database was downloaded, but could not be cached due to a missing version."
+      );
+      return malwareDatabase;
+    }
   } catch (/** @type any */ error) {
     if (cachedDatabase) {
       ui.writeWarning(
diff --git a/packages/safe-chain/src/utils/safeSpawn.js b/packages/safe-chain/src/utils/safeSpawn.js
index 489d070..e17bdb5 100644
--- a/packages/safe-chain/src/utils/safeSpawn.js
+++ b/packages/safe-chain/src/utils/safeSpawn.js
@@ -67,8 +67,6 @@ function resolveCommandPath(command) {
   // Use 'command -v' to find the full path
   const fullPath = execSync(`command -v ${command}`, {
     encoding: "utf8",
-    // @ts-expect-error shell is a string option
-    shell: true,
   }).trim();
 
   if (!fullPath) {
@@ -120,8 +118,12 @@ export async function safeSpawn(command, args, options = {}) {
     });
 
     child.on("close", (code) => {
+      // Code is null if it terminated by a signal. This should never
+      // happen in our code. If this happens, return 1 error code.
+
+      code = code ?? 1;
+
       resolve({
-        // @ts-expect-error code can be null
         status: code,
         stdout: stdout,
         stderr: stderr,