b2 would not respect windows sdk environment variable loaded by VS Command Prompt

[elfive]

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Environment and version details

• Operating System+version: Windows 10 x64 22H2 19045.5737
• Compiler+version: msvc-14.0
• Shell: cmd
• B2 Version: B2 5.3.3 (OS=NT, jobs=16)
• B2 Configuration: Output of b2 --toolset=msvc-14.0 architecture=x86 address-model=64 variant=release link=static runtime-link=shared --build-dir="D:\Libraries\build\static\vs2015\boost-1.74.0\x64\Release" install --prefix="D:\Libraries\lib\static\vs2015\boost-1.74.0\x64\Release" threading=multi --build-type=complete -sBOOST_PYTHON_STATIC_LIB=1 python="3.11" -sZLIB_SOURCE="D:/Libraries/source/zlib-1.3.1" -sBZIP2_SOURCE="D:/Libraries/source/bzip2-1.0.8" -q -a --reconfigure --no-cmake-config --debug-configuration >> logs.txt
• Boost Version: 1.74.0

[logs.txt](https://github.com/user-attachments/files/23379133/logs.txt)

Brief problem description

without windows sdk 10.0.26100.0 installed, everything works, compile without error.
but with windows sdk 10.0.26100.0 installed, error occurred,
I tried override environment variable related to windows sdk after vcvarsall.bat amd64 8.1 loaded, not working.

Steps to reproduce the issue

0. install Visual Studio 2015 and Windows SDK 8.1, boost 1.74.0 should build without any problem
1. Install Windows SDK 10.0.26100.0
2. Open cmd.exe
3. Run vcvarsall.bat amd64 8.1
4. Change to boost-1.74.0 source directory and run command (of course, minimal command b2 also lead to the same problem): b2 --toolset=msvc-14.0 architecture=x86 address-model=64 variant=release link=static runtime-link=shared --build-dir="D:\Libraries\build\static\vs2015\boost-1.74.0\x64\Release" install --prefix="D:\Libraries\lib\static\vs2015\boost-1.74.0\x64\Release" threading=multi --build-type=complete -sBOOST_PYTHON_STATIC_LIB=1 python="3.11" -sZLIB_SOURCE="D:/Libraries/source/zlib-1.3.1" -sBZIP2_SOURCE="D:/Libraries/source/bzip2-1.0.8" -q -a --reconfigure --no-cmake-config

Actual behavior summary

When I run the b2 command, b2 compile should load specified environment instead of load the latest windows sdk environment installed and I think it shouldn't.

[logs_with_d2.txt](https://github.com/user-attachments/files/23379315/logs_with_d2.txt)

Expected behavior summary

b2 should load correct environment.

[grisumbras]

The correct argument for b2 is toolset not --toolset (which is an argument for the bootstrap script).

[elfive]

The correct argument for b2 is toolset not --toolset (which is an argument for the bootstrap script).

thx for correct, but still got the same error, first error log:

compile-c-c++ D:\Libraries\build\static\vs2015\boost-1.74.0\x64\Release\boost\bin.v2\libs\regex\build\msvc-14.0\release\link-static\threading-multi\c_regex_traits.obj
c_regex_traits.cpp
C:\Program Files (x86)\Windows Kits\10\include\10.0.26100.0\ucrt\wchar.h(316): error C3861: “_mm_loadu_si64”: identifier not found

    call "D:\Libraries\build\static\vs2015\boost-1.74.0\x64\Release\boost\bin.v2\standalone\msvc\msvc-14.0\msvc-setup.bat" amd64 >nul
 cl /Zm800 -nologo "libs\regex\build\..\src\c_regex_traits.cpp" -c -Fo"D:\Libraries\build\static\vs2015\boost-1.74.0\x64\Release\boost\bin.v2\libs\regex\build\msvc-14.0\release\link-static\threading-multi\c_regex_traits.obj"     -TP /wd4675 /EHs /GR /Zc:throwingNew /O2 /Ob2 /W4 /MD /Zc:forScope /Zc:wchar_t /Zc:inline /Gw /favor:blend -DBOOST_ALL_NO_LIB=1 -DNDEBUG "-I."

...failed compile-c-c++ D:\Libraries\build\static\vs2015\boost-1.74.0\x64\Release\boost\bin.v2\libs\regex\build\msvc-14.0\release\link-static\threading-multi\c_regex_traits.obj...

full log uploaded.
build_log.txt