pnpm install: Disable strict-peer-dependencies and improve error mess…

…aging. (#1191)

src/index.ts

@@ -112,8 +112,34 @@ const npmInstall = async (
         const packageManager = await getPackageManagerForInstall(options, pkgFile)
         const cmd = packageManager + (process.platform === 'win32' ? '.cmd' : '')
         const cwd = options.cwd || path.resolve(pkgFile, '..')
-        const stdout = await spawn(cmd, ['install'], { cwd })
-        print(options, stdout, 'verbose')
+        let stdout = ''
+        try {
+          await spawn(cmd, ['install'], {
+            cwd,
+            ...(packageManager === 'pnpm'
+              ? {
+                  env: {
+                    ...process.env,
+                    // With spawn, pnpm install will fail with ERR_PNPM_PEER_DEP_ISSUES  Unmet peer dependencies.
+                    // When pnpm install is run directly from the terminal, this error does not occur.
+                    // When pnpm install is run from a simple spawn script, this error does not occur.
+                    // The issue only seems to be when pnpm install is executed from npm-check-updates, but it's not clear what configuration or environmental factors are causing this.
+                    // For now, turn off strict-peer-dependencies on pnpm autoinstall.
+                    // See: https://github.com/raineorshine/npm-check-updates/issues/1191
+                    npm_config_strict_peer_dependencies: false,
+                  },
+                }
+              : null),
+            stdout: (data: string) => {
+              stdout += data
+            },
+          })
+          print(options, stdout, 'verbose')
+        } catch (err: any) {
+          // sometimes packages print errors to stdout instead of stderr
+          // if there is nothing on stderr, reject with stdout
+          throw new Error(err?.message || err || stdout)
+        }
       })
     }
   }