npm：即使安装了virtualenv，也无法运行virtualenv命令

Question

即使在全局安装virtualenv之后，virtualenv命令也无法识别。安装过程中注意到的一件事是消息：

npm WARN deprecated minimatch@0.3.0: Please update to minimatch 3.0.2 or higher.

可能是什么原因。 我正在使用npm版本3.6.0和节点版本5.6.0的Win7平台上工作。

以下是相同的快照。

to avoid a RegExp DoS issue
c:\>npm install -g virtualenv
npm WARN deprecated minimatch@0.3.0: Please update to minimatch 3.0.2 or higher
to avoid a RegExp DoS issue
C:\Users\<user>\AppData\Roaming\npm\virtualenv-postinstall -> C:\Users\<user>\AppData\Roaming\npm\node_modules\virtualenv\bin\postinstall
C:\Users\<user>\AppData\Roaming\npm
`-- virtualenv@0.3.1
  +-- glob@3.2.11
  | +-- inherits@2.0.3
  | `-- minimatch@0.3.0
  |   +-- lru-cache@2.7.3
  |   `-- sigmund@1.0.1
  +-- request@2.81.0
  | +-- aws-sign2@0.6.0
  | +-- aws4@1.6.0
  | +-- caseless@0.12.0
  | +-- combined-stream@1.0.5
  | | `-- delayed-stream@1.0.0
  | +-- extend@3.0.1
  | +-- forever-agent@0.6.1
  | +-- form-data@2.1.4
  | | `-- asynckit@0.4.0
  | +-- har-validator@4.2.1
  | | +-- ajv@4.11.8
  | | | +-- co@4.6.0
  | | | `-- json-stable-stringify@1.0.1
  | | |   `-- jsonify@0.0.0
  | | `-- har-schema@1.0.5
  | +-- hawk@3.1.3
  | | +-- boom@2.10.1
  | | +-- cryptiles@2.0.5
  | | +-- hoek@2.16.3
  | | `-- sntp@1.0.9
  | +-- http-signature@1.1.1
  | | +-- assert-plus@0.2.0
  | | +-- jsprim@1.4.0
  | | | +-- assert-plus@1.0.0
  | | | +-- extsprintf@1.0.2
  | | | +-- json-schema@0.2.3
  | | | `-- verror@1.3.6
  | | `-- sshpk@1.13.1
  | |   +-- asn1@0.2.3
  | |   +-- assert-plus@1.0.0
  | |   +-- bcrypt-pbkdf@1.0.1
  | |   +-- dashdash@1.14.1
  | |   | `-- assert-plus@1.0.0
  | |   +-- ecc-jsbn@0.1.1
  | |   +-- getpass@0.1.7
  | |   | `-- assert-plus@1.0.0
  | |   +-- jsbn@0.1.1
  | |   `-- tweetnacl@0.14.5
  | +-- is-typedarray@1.0.0
  | +-- isstream@0.1.2
  | +-- json-stringify-safe@5.0.1
  | +-- mime-types@2.1.15
  | | `-- mime-db@1.27.0
  | +-- oauth-sign@0.8.2
  | +-- performance-now@0.2.0
  | +-- qs@6.4.0
  | +-- safe-buffer@5.1.1
  | +-- stringstream@0.0.5
  | +-- tough-cookie@2.3.2
  | | `-- punycode@1.4.1
  | +-- tunnel-agent@0.6.0
  | `-- uuid@3.1.0
  +-- rimraf@2.6.1
  | `-- glob@7.1.2
  |   +-- fs.realpath@1.0.0
  |   +-- inflight@1.0.6
  |   | `-- wrappy@1.0.2
  |   +-- minimatch@3.0.4
  |   | `-- brace-expansion@1.1.8
  |   |   +-- balanced-match@1.0.0
  |   |   `-- concat-map@0.0.1
  |   +-- once@1.4.0
  |   `-- path-is-absolute@1.0.1
  +-- semver@5.3.0
  +-- tar@2.2.1
  | +-- block-stream@0.0.9
  | `-- fstream@1.0.11
  |   +-- graceful-fs@4.1.11
  |   `-- mkdirp@0.5.1
  |     `-- minimist@0.0.8
  `-- xmlrpc@0.8.1
    +-- node-xml@1.0.0
    `-- xmlbuilder@0.1.2


c:\>virtualenv venv
'virtualenv' is not recognized as an internal or external command,
operable program or batch file.