vscode-esp-idf-extension: Error on build in version 0.2.1 (VSC-316)

Describe the bug Build randomly fails with error: “Make sure you have the build tools installed and set in $PATH”. After a restart it usually works, but not always. When it fails, there is no message in “ESP-IDF Build” output. The behavior is the same whether esp-idf is installed using the Windows installer or the wizard in the extension.

Downgrading the extension to 0.2.0 solves the problem.

To Reproduce

1. Install ESP-IDF using Windows installer or using the wizard in the vscode-esp-idf extension.
2. Run either “ESP-IDF: Build your project” task or click the build button in status bar.

Expected behavior Project gets build as ESP-IDF is installed and the extension is correctly configured.

Environment (please complete the following information):

• OS Name & Version: Windows 10 1909
• VSCode Version: 1.44.2
• ESP-IDF Version: 4.0.0
• Python Version: 3.8

Logs

{"user":true,"message":"Make sure you have the build tools installed and set in $PATH","stack":"Error: spawn cmake ENOENT\n\tat Process.ChildProcess._handle.onexit (internal/child_process.js:264:19)\n\tat onErrorNT (internal/child_process.js:456:16)\n\tat processTicksAndRejections (internal/process/task_queues.js:77:11)","level":"error","timestamp":"2020-05-02T20:03:51.383Z"}