I’m using Visual Studio Code 1.93.0 in Ubuntu 24.04 with the following extensions:

• C/C++ v1.22.2
• ESP-IDF v1.8.1
• PlatformIO IDE v3.3.3

and some others that should not matter for the specific question.
When I open a project that uses PlatformIO IDE and C++ the IntelliSense works fine: syntax highlight, auto-completion, navigation (declarations/implementations), refactoring, etc…

Since a few days, when I open a project that uses ESP-IDF and C, it takes several minutes before all the above features are available. And every time I save a file, they stop to work for another few minutes.

I tried to:

• C/C++ Reset IntelliSense database
• C/C++ Rescan Workspace
• check for VSC updates
• check for extensions updates

But nothing fixed the issue.
I also noticed that every time I save a file (and until the features are available again) the process cpptools-srv is quite active, with about 4% CPU and minimal RAM usage. Hence I don’t think it’s the same issue described here.

Here is my settings.json:

{
    "configurations": [
        {
            "name": "Linux",
            "includePath": [
                "${workspaceFolder}/**",
                "${config:idf.espIdfPath}/components/**"                
            ],
            "defines": [],
            "compilerPath": "${config:idf.toolsPath}/tools/xtensa-esp-elf/esp-13.2.0_20240530/xtensa-esp-elf/bin/xtensa-esp32s3-elf-gcc",
            "cStandard": "c17",
            "cppStandard": "gnu++17",
            "intelliSenseMode": "linux-gcc-x64"
        }
    ],
    "version": 4
}

and my c_cpp_properties.json:

{
    "idf.adapterTargetName": "esp32s3",
    "idf.flashType": "UART",
    "idf.port": "/dev/ttyACM0",
    "files.associations": {
        "usb_serial_jtag_vfs.h": "c",
        "uart_vfs.h": "c",
        "common.h": "c",
        "i2c_master.h": "c",
        "modbus_params.h": "c",
        "esp_mac.h": "c",
        "freertos.h": "c",
        "datetime.h": "c",
        "time.h": "c",
        "time_t.h": "c",
        "condition_variable": "c",
        "ctime": "c",
        "mutex": "c",
        "shared_mutex": "c",
        "spi_master.h": "c",
        "task_wifi.h": "c"
    }
}

UPDATE

Following the hint of user starball I ran the extension bisect and I found out the culprit is ms-vscode.cpptools. Of course disabling the extension is not the solution! It’s odd that with other projects it works fine.

How to find out the root cause of the issue?