Warn when man or bin directory not found but don't crash

src/reporters/lang/en.js

@@ -31,6 +31,7 @@ const messages = {
   manifestStringExpected: '$0 is not a string',
   manifestDependencyBuiltin: 'Dependency $0 listed in $1 is the name of a built-in module',
   manifestDependencyCollision: '$0 has dependency $1 with range $2 that collides with a dependency in $3 of the same name with version $4',
+  manifestDirectoryNotFound: 'Unable to read $0 directory of module $1',
 
   configSet: 'Set $0 to $1.',
   configDelete: 'Deleted $0.',

src/util/normalize-manifest/fix.js

@@ -20,10 +20,13 @@ type Dict<T> = {
   [key: string]: T;
 };
 
+type WarnFunction = (msg: string) => void;
+
 export default async function (
   info: Dict<mixed>,
   moduleLoc: string,
   reporter: Reporter,
+  warn: WarnFunction,
   looseSemver: boolean,
 ): Promise<void> {
   const files = await fs.readdir(moduleLoc);
@@ -184,24 +187,34 @@ export default async function (
 
     if (!info.bin && binDir && typeof binDir === 'string') {
       const bin = info.bin = {};
+      const fullBinDir = path.join(moduleLoc, binDir);
 
-      for (const scriptName of await fs.readdir(path.join(moduleLoc, binDir))) {
-        if (scriptName[0] === '.') {
-          continue;
+      if (await fs.exists(fullBinDir)) {
+        for (const scriptName of await fs.readdir(fullBinDir)) {
+          if (scriptName[0] === '.') {
+            continue;
+          }
+          bin[scriptName] = path.join('.', binDir, scriptName);
         }
-        bin[scriptName] = path.join('.', binDir, scriptName);
+      } else {
+        warn(reporter.lang('manifestDirectoryNotFound', binDir, info.name));
       }
     }
 
     const manDir = dirs.man;
 
     if  (!info.man && typeof manDir === 'string') {
       const man = info.man = [];
+      const fullManDir = path.join(moduleLoc, manDir);
 
-      for (const filename of await fs.readdir(path.join(moduleLoc, manDir))) {
-        if (/^(.*?)\.[0-9]$/.test(filename)) {
-          man.push(path.join('.', manDir, filename));
+      if (await fs.exists(fullManDir)) {
+        for (const filename of await fs.readdir(fullManDir)) {
+          if (/^(.*?)\.[0-9]$/.test(filename)) {
+            man.push(path.join('.', manDir, filename));
+          }
         }
+      } else {
+        warn(reporter.lang('manifestDirectoryNotFound', manDir, info.name));
       }
     }
   }

src/util/normalize-manifest/index.js

@@ -13,8 +13,6 @@ export default async function (
   config: Config,
   isRoot: boolean,
 ): Promise<Manifest> {
-  await fix(info, moduleLoc, config.reporter, config.looseSemver);
-
   // create human readable name
   const {name, version} = info;
   let human: ?string;
@@ -35,6 +33,7 @@ export default async function (
     config.reporter.warn(msg);
   }
 
+  await fix(info, moduleLoc, config.reporter, warn, config.looseSemver);
   try {
     validate(info, isRoot, config.reporter, warn);
   } catch (err) {