conan b2 command cannot find vcvarsall.bat when VS2022 build tools are installed to a different directory from VS2022

[devivoc]

After running into this issue and updating my b2 dependency, I ran into this issue.
This issue occurs because Chocolatey installs Visual Studio 2022 build tools to C:\Program Files (x86)\Microsoft Visual Studio\2022\Build Tools but it installs Visual Studio 2022 itself to C:\Program Files\Microsoft Visual Studio\2022\Professional. This problem is acknowledged here. I also think it is possible on normal installations via the Visual Studio Installer, depending on what the Install Location is set at.

Configuration:
conan: 1.59.0
boost: 1.81.0
b2: 4.9.6
python: 3.7.7

The smallest action I can take to recreate this issue is:

• choco install visualstudio2022professional
• choco install visualstudio2022buildtools
• choco install visualstudio2022-workload-nativedesktop

make sure the conan compiler is Visual Studio and the version 17

Configuration for profile default:

[settings]
os=Windows
os_build=Windows
arch=x86_64
arch_build=x86_64
compiler=Visual Studio
compiler.version=17
build_type=Debug
[options]
[conf]
[build_requires]
[env]

make sure you at least have conancenter as a conan remote
conancenter: https://center.conan.io [Verify SSL: True]

and then do
conan install boost/1.81.0@ --build=missing

here is the error output:

boost/1.81.0: Applying build-requirement: b2/4.9.6
Downloading conan_sources.tgz completed [0.75k]
Decompressing conan_sources.tgz completed [0.00k]
boost/1.81.0: Configuring sources in C:\.conan\c8ce608d1ce0d\1\src
Downloading boost_1_81_0.tar.bz2 completed [116013.43k]                                  boost/1.81.0: /1.81.0:
boost/1.81.0:
boost/1.81.0: Apply patch (conan): Fails the build when mpi is not configured
boost/1.81.0: Apply patch (conan): Fails the build when there is no iconv backend
boost/1.81.0: Building your package in C:\.conan\65292aba\1
boost/1.81.0: Generator txt created conanbuildinfo.txt
boost/1.81.0: Calling generate()
boost/1.81.0: Aggregating env generators
boost/1.81.0: Calling build()
boost/1.81.0: WARN: replace_in_file didn't find pattern '/* thread_local */' in 'C:\.conan\c8ce608d1ce0d\1\src\boost\sta
cktrace\detail\libbacktrace_impls.hpp' file.
boost/1.81.0: WARN: replace_in_file didn't find pattern '/* static __thread */' in 'C:\.conan\c8ce608d1ce0d\1\src\boost\
stacktrace\detail\libbacktrace_impls.hpp' file.
boost/1.81.0: WARN: replace_in_file didn't find pattern 'local generic-os = [ set.difference $(all-os) : aix darwin vxwo
rks solaris osf hpux ] ;' in 'C:\.conan\c8ce608d1ce0d\1\src\tools\build\src\tools\gcc.jam' file.
boost/1.81.0: WARN: replace_in_file didn't find pattern 'local no-threading = android beos haiku sgi darwin vxworks ;' i
n 'C:\.conan\c8ce608d1ce0d\1\src\tools\build\src\tools\gcc.jam' file.
boost/1.81.0: WARN: Patching user-config.jam
boost/1.81.0: WARN: Using the new toolchains and generators without specifying a build profile (e.g: -pr:b=default) is d
iscouraged and might cause failures and unexpected behavior
boost/1.81.0: WARN:
using zlib : 1.2.13 : <include>"C:/Users/cdevivo/.conan/data/zlib/1.2.13/_/_/package/164640aad040835ac89882393a96d892006
94f04/include" <search>"C:/Users/cdevivo/.conan/data/zlib/1.2.13/_/_/package/164640aad040835ac89882393a96d89200694f04/li
b" <name>zlib ;
using bzip2 : 1.0.8 : <include>"C:/Users/cdevivo/.conan/data/bzip2/1.0.8/_/_/package/d74f69022acf854c1ce6f27efa07ccbb650
4e4b1/include" <search>"C:/Users/cdevivo/.conan/data/bzip2/1.0.8/_/_/package/d74f69022acf854c1ce6f27efa07ccbb6504e4b1/li
b" <name>bz2 ;
using "msvc" : 14.3 :  :
 ;
boost/1.81.0: WARN: b2 -q numa=on target-os=windows architecture=x86 address-model=64 binary-format=pe abi=ms --layout=s
ystem --user-config=C:\.conan\c8ce608d1ce0d\1\src\tools\build\user-config.jam -sNO_ZLIB=0 -sNO_BZIP2=0 -sNO_LZMA=1 -sNO_
ZSTD=1 boost.locale.icu=off --disable-icu boost.locale.iconv=off --disable-iconv runtime-link=shared runtime-debugging=o
n threading=multi visibility=hidden link=static variant=debug --with-atomic --with-chrono --with-container --with-contex
t --with-contract --with-coroutine --with-date_time --with-exception --with-fiber --with-filesystem --with-graph --with-
iostreams --with-json --with-locale --with-log --with-math --with-nowide --with-program_options --with-random --with-reg
ex --with-serialization --with-stacktrace --with-system --with-test --with-thread --with-timer --with-type_erasure --wit
h-url --with-wave toolset=msvc pch=on linkflags="" cxxflags="-fPIC" install --prefix=C:\.conan\6caa724c0\1 -j8 --abbrevi
ate-paths -d0 --debug-configuration --build-dir="C:\.conan\65292aba\1\build-debug"
The system cannot find the path specified.
boost/1.81.0:
boost/1.81.0: ERROR: Package 'c16d614bb966cd4b029ded7ef4fdc14b694dd24c' build failed
boost/1.81.0: WARN: Build folder C:\.conan\65292aba\1\build-debug
ERROR: boost/1.81.0: Error in build() method, line 887
        self.run(full_command)
        ConanException: Error 1 while executing b2 -q numa=on target-os=windows architecture=x86 address-model=64 binary
-format=pe abi=ms --layout=system --user-config=C:\.conan\c8ce608d1ce0d\1\src\tools\build\user-config.jam -sNO_ZLIB=0 -s
NO_BZIP2=0 -sNO_LZMA=1 -sNO_ZSTD=1 boost.locale.icu=off --disable-icu boost.locale.iconv=off --disable-iconv runtime-lin
k=shared runtime-debugging=on threading=multi visibility=hidden link=static variant=debug --with-atomic --with-chrono --
with-container --with-context --with-contract --with-coroutine --with-date_time --with-exception --with-fiber --with-fil
esystem --with-graph --with-iostreams --with-json --with-locale --with-log --with-math --with-nowide --with-program_opti
ons --with-random --with-regex --with-serialization --with-stacktrace --with-system --with-test --with-thread --with-tim
er --with-type_erasure --with-url --with-wave toolset=msvc pch=on linkflags="" cxxflags="-fPIC" install --prefix=C:\.con
an\6caa724c0\1 -j8 --abbreviate-paths -d0 --debug-configuration --build-dir="C:\.conan\65292aba\1\build-debug"

Took me a while to figure out what the path was that it was missing. It could not find vcvarsall.bat. Inspecting the conanfile I found that the VCVars class in ~\Python\Python37\site-packages\conan\tools\microsoft\visual.py just appends the path "VC/Auxilary/Build/vcvarsall.bat" to wherever Visual Studio is installed, assuming that path will be correct.

For my use, I was able to just use a hack in my conan config to override the installation path for VS2022 (I understand that I could also specify an install path with chocolatey for the build tools, or I could have edited the boost conanfile) because I only used one compiler and one version. That hack was

conan config set tools.microsoft.msbuild:installation_path="C:\Program Files (x86)\Microsoft Visual Studio\2022\Build Tools

While the assumption is being made by Microsoft's python, it still an assumption that can cause VS2022 configurations with boost to fail. The error message could have at least been more helpful.