node-bluetooth causing build error

还没有人认领这个 Issue。

**Environments :**
- **_Windows 10_** version 1903
- Visual Studio Enterprise **_2019_**
- Python **_2.7_**
- node **_v12.9.1_**
- node-gyp **_v5.0.3_**

**The problem**
I was trying to use [ESCPOS_2.5.2](https://github.com/song940/node-escpos) when node-gyp start building the ( node-bluetooth ) module, warnings and errors start to pop on the console till

>gyp ERR! build error
gyp ERR! stack Error: "C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\MSBuild\Current\Bin\MSBuild.exe" failed with exit code: 1
gyp ERR! stack at ChildProcess.onExit (C:\Users\xxxx\AppData\Roaming\npm\node_modules\node-gyp\lib\build.js:196:23)
gyp ERR! stack at ChildProcess.emit (events.js:209:13)
gyp ERR! stack at Process.ChildProcess._handle.onexit (internal/child_process.js:272:12)
gyp ERR! System Windows_NT 10.0.18362
gyp ERR! command "C:\\Program Files\\nodejs\\node.exe" "C:\\Users\\xxxx\\AppData\\Roaming\\npm\\node_modules\\node-gyp\\bin\\node-gyp.js" "configure" "build"
gyp ERR! cwd D:\_Node_field\pos_printer\node_modules\node-bluetooth
gyp ERR! node -v v12.9.1
gyp ERR! node-gyp -v v5.0.3
gyp ERR! not ok
npm WARN pos_printer@1.0.0 No repository field.
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: node-bluetooth@1.2.6 (node_modules\node-bluetooth):
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: node-bluetooth@1.2.6 install: `node-gyp configure build`
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: Exit status

is something with the environment causing the problem?

首先，在报告的 Windows 10、Node v12.9.1、Python 2.7、Visual Studio 2019 和 node-gyp v5.0.3 环境中重现 node-bluetooth@1.2.6 的安装。检查 node_modules\node-bluetooth 目录中的 node-gyp configure/build 输出，并确定是什么阻止了构建完成；完成的标准是模块能够在不出现报告中的构建错误的情况下安装。

由索引模型根据 Issue 内容生成。