1.2.x Possible False activated `-vswhere-version` key. (400) Bad Request, etc

[3F]

Found this today before new DllExport release.

For example:
https://ci.appveyor.com/project/3Fs/dllexport/build/build-102

9:03:09 PM.4121 [INFO]: Result of the command: `selected new vswhere version: "MvsSln.sln"`
9:03:11 PM.4982 [INFO]: stderr: received '55'
9:03:11 PM.4982 [WARN]: The command has been executed with error: `The remote server returned an error: (400) Bad Request.`
9:03:11 PM.5672 [INFO]: stderr: received '42'
9:03:11 PM.5672 [WARN]: The command has been executed with error: `The system cannot find the path specified.`
9:03:11 PM.5792 [INFO]: stdout: received '75'
9:03:11 PM.5792 [INFO]: Result of the command: `hMSBuild: "\MSBuild\C:\projects\dllexport\tools\vswhere.0\Bin\MSBuild.exe" `
9:03:11 PM.5792 [INFO]: stderr: received '66'
9:03:11 PM.5792 [WARN]: The command has been executed with error: `The filename, directory name, or volume label syntax is incorrect.`
9:03:11 PM.5792 [INFO]: stderr: received '15'
9:03:11 PM.5792 [WARN]: The command has been executed with error: ` Build failed. `
9:03:11 PM.5792 [INFO]: [Pre] finished SBE: Custom build for dependencies ...

And this is why:

:: 1.2.2 minified version
if "!an:~0,16!"=="-vswhereVersion " set as=1
if "!an:~0,17!"=="-vswhere-version " set as=1
if defined as (            <<<<<<<<<<<<^^^^^^^ 
set "as="
call :be %1 & shift
set aj=%2
echo selected new vswhere version: !aj!
call :be %2 & shift
)

the as can be defined outside current env but we have no set "as=" before this block.

Affects for any editions from 1.2.x. However, full version less prone to errors because of more long name.

You can try to avoid this error via local scope, for example, for minified and the light edition it can be like:

setlocal & (set "as=" & cd MvsSln & build PublicRelease) & endlocal

[3F]

Modern 2.0 was based on other logic and works well.

So please consider upgrading your versions as soon as possible to avoid some unpredictable behavior.