Thanks for the report.

Can you confirm if you are running Debug > Start Debugging, or Debug > Attach to Process?

Thanks for confirming the actions, and its the build process which is taking a long time from your report.

This is due to how the <SrcWrapper.h> is added as part of the build process, which causes the Deep Search to assess a large number of files every build.

The Build process can be faster, by Disabling the Compiler > Deep Search option, BUT you will need to add in the SrcWrapper.h and all other library and header files which need to be included.

// Top of Main Sketch INO File
// Avoid Official STM32 Build Time: --> Add these #includes, and all other library headers, then disable vMicro > Compiler > Deep Search
#include <SrcWrapper.h>
 

Thanks for the detail, and the uploader in use here seems to be the STM32Cube Programmer via Serial, which is part of the core package.

Is this faster if you select the "STLinkv2.1 + OpenOCD (vMicro)" as the uploader?
(This will use OpenOCD to connect to the STLink and upload the code via the programmer)

Hi, I tried as suggested, but the results are the same. For some reason Serial upload is auto selected. I am attaching the screenshot for your reference.

It has failed to program.

If I choose STlink (SWD), although it took a long time but it programmed the chip.

>>Can you confirm if the failed upload via the vMicro OpenOCD option was as slow as the previous ones? (around a minute)

Yes.

>>Does the upload via the STLink (SWD) report progress during the upload? (or just appear to hang)

ST-LINK FW  : V2J37S7
Voltage     : 3.25V
SWD freq    : 4000 KHz
Connect mode: Under Reset
Reset mode  : Hardware reset
Device ID   : 0x419
Device name : STM32F42xxx/F43xxx
Flash size  : 1 MBytes
Device type : MCU
Device CPU  : Cortex-M4
Memory Programming ...
Opening and parsing file: MnC2test.ino.bin
  File          : MnC2test.ino.bin
  Size          : 76760 Bytes
  Address       : 0x08000000
Erasing memory corresponding to segment 0:
Erasing internal memory sectors [0 4]
Download in Progress:
File download complete
Time elapsed during download operation: 00:00:02.817
	The upload process has finished.
# Copy build result to 'Project>Property Pages>Intermediate Directory'
# Destination: file:///D:/xxxx/MnC2test/Debug/
RUNNING Program ...

  Address:      : 0x8000000
Warning: The core is halted
Start operation achieved successfully 

Thanks for confirming the vMicro failed upload took as long, which is odd as it should fail virtually instantly.

The "unresponsive" prompt will be due to vMicro waiting on the upload process to complete, but it is not our code running at this point.

The upload snippet above shows a time elapsed of 2.817s, but your experience is the upload alone is taking > 1minute? 
(use the vMicro > Uploader > Upload Last Build to test upload in isolation)

Is it the same in the Arduino IDE using the same sketch and programming method?

Apologies if repeat questions, I'm just trying to make sure I understand the issue fully.

Thanks for the detail.

Debug > Start - This will take around a minute as it rebuilds the solution, and re-uploads it.
Debug > Attach - This should be quick to attach once programmed, and only attaches the debugging process.

Could you follow the steps below to reveal further information for us:
1) Add the attached entries to a board.txt in your project (Right click project in Solution Explorer > Add > Local Board.txt) and Restart VS
2) Set the Compiler > Verbose, and Compiler > Show Build Properties
3) Perform the "Build and Upload" process.
4) After this please attach the BuildTimings.txt file it generates, and the entire Build Output

Thanks for the timings and detail.

Could you please also attach the output from Output Window, for a build and upload?  (with the settings set as shown at the top of the page)

There is some improvements. I can program immediately if I commnet out the 

"recipe.hooks.postbuild.2.pattern=notepad.exe {ProjectDir}BuildTimings.txt"

This was tested on Win 7. I will check with other Win 10.

There is another issue with Debug. I cannot "Start debug" but only "Attach to Process".

Any Idea, why?