Download MSVC compiler/linker & Windows SDK without installing full Visual Studio

!README.md

This downloads standalone MSVC compiler, linker & other tools, also headers/libraries from Windows SDK into portable folder, without installing Visual Studio. Has bare minimum components - no UWP/Store/WindowsRT stuff, just files & tools for native desktop app development.

Run py.exe portable-msvc.py and it will download output into msvc folder. By default it will download latest available MSVC & Windows SDK - currently v14.40.33807 and v10.0.26100.0.

You can list available versions with py.exe portable-msvc.py --show-versions and then pass versions you want with --msvc-version and --sdk-version arguments.

To use cl.exe/link.exe first run setup_TARGET.bat - after that PATH/INCLUDE/LIB env variables will be updated to use all the tools as usual. You can also use clang-cl.exe with these includes & libraries.

To use clang-cl.exe without running setup.bat, pass extra /winsysroot msvc argument (msvc is folder name where output is stored).

portable-msvc.py

#!/usr/bin/env python3

import io
import os
import sys
import stat
import json
import shutil
import hashlib
import zipfile
import tempfile
import argparse
import subprocess
import urllib.error
import urllib.request
from pathlib import Path

OUTPUT = Path("msvc")         # output folder
DOWNLOADS = Path("downloads") # temporary download files

# NOTE: not all host & target architecture combinations are supported

DEFAULT_HOST = "x64"
ALL_HOSTS    = "x64 x86 arm64".split()

DEFAULT_TARGET = "x64"
ALL_TARGETS    = "x64 x86 arm arm64".split()

MANIFEST_URL = "https://aka.ms/vs/17/release/channel"
MANIFEST_PREVIEW_URL = "https://aka.ms/vs/17/pre/channel"

ssl_context = None

def download(url):
  with urllib.request.urlopen(url, context=ssl_context) as res:
    return res.read()

total_download = 0

def download_progress(url, check, filename):
  fpath = DOWNLOADS / filename
  if fpath.exists():
    data = fpath.read_bytes()
    if hashlib.sha256(data).hexdigest() == check.lower():
      print(f"\r{filename} ... OK")
      return data

  global total_download
  with fpath.open("wb") as f:
    data = io.BytesIO()
    with urllib.request.urlopen(url, context=ssl_context) as res:
      total = int(res.headers["Content-Length"])
      size = 0
      while True:
        block = res.read(1<<20)
        if not block:
          break
        f.write(block)
        data.write(block)
        size += len(block)
        perc = size * 100 // total
        print(f"\r{filename} ... {perc}%", end="")
    print()
    data = data.getvalue()
    digest = hashlib.sha256(data).hexdigest()
    if check.lower() != digest:
      exit(f"Hash mismatch for f{pkg}")
    total_download += len(data)
    return data

# super crappy msi format parser just to find required .cab files
def get_msi_cabs(msi):
  index = 0
  while True:
    index = msi.find(b".cab", index+4)
    if index < 0:
      return
    yield msi[index-32:index+4].decode("ascii")

def first(items, cond = lambda x: True):
  return next((item for item in items if cond(item)), None)
  

### parse command-line arguments

ap = argparse.ArgumentParser()
ap.add_argument("--show-versions", action="store_true", help="Show available MSVC and Windows SDK versions")
ap.add_argument("--accept-license", action="store_true", help="Automatically accept license")
ap.add_argument("--msvc-version", help="Get specific MSVC version")
ap.add_argument("--sdk-version", help="Get specific Windows SDK version")
ap.add_argument("--preview", action="store_true", help="Use preview channel for Preview versions")
ap.add_argument("--target", default=DEFAULT_TARGET, help=f"Target architectures, comma separated ({','.join(ALL_TARGETS)})")
ap.add_argument("--host", default=DEFAULT_HOST, help=f"Host architecture", choices=ALL_HOSTS)
args = ap.parse_args()

host = args.host
targets = args.target.split(',')
for target in targets:
  if target not in ALL_TARGETS:
    exit(f"Unknown {target} target architecture!")


### get main manifest

URL = MANIFEST_PREVIEW_URL if args.preview else MANIFEST_URL

try:
  manifest = json.loads(download(URL))
except urllib.error.URLError as err:
  import ssl
  if isinstance(err.args[0], ssl.SSLCertVerificationError):
    # for more info about Python & issues with Windows certificates see https://stackoverflow.com/a/52074591
    print("ERROR: ssl certificate verification error")
    try:
      import certifi
    except ModuleNotFoundError:
      print("ERROR: please install 'certifi' package to use Mozilla certificates")
      print("ERROR: or update your Windows certs, see instructions here: https://woshub.com/updating-trusted-root-certificates-in-windows-10/#h2_3")
      exit()
    print("NOTE: retrying with certifi certificates")
    ssl_context = ssl.create_default_context(cafile=certifi.where())
    manifest = json.loads(download(URL))
  else:
    raise

### download VS manifest

ITEM_NAME = "Microsoft.VisualStudio.Manifests.VisualStudioPreview" if args.preview else "Microsoft.VisualStudio.Manifests.VisualStudio"

vs = first(manifest["channelItems"], lambda x: x["id"] == ITEM_NAME)
payload = vs["payloads"][0]["url"]

vsmanifest = json.loads(download(payload))


### find MSVC & WinSDK versions

packages = {}
for p in vsmanifest["packages"]:
  packages.setdefault(p["id"].lower(), []).append(p)

msvc = {}
sdk = {}

for pid,p in packages.items():
  if pid.startswith("Microsoft.VisualStudio.Component.VC.".lower()) and pid.endswith(".x86.x64".lower()):
    pver = ".".join(pid.split(".")[4:6])
    if pver[0].isnumeric():
      msvc[pver] = pid
  elif pid.startswith("Microsoft.VisualStudio.Component.Windows10SDK.".lower()) or \
       pid.startswith("Microsoft.VisualStudio.Component.Windows11SDK.".lower()):
    pver = pid.split(".")[-1]
    if pver.isnumeric():
      sdk[pver] = pid

if args.show_versions:
  print("MSVC versions:", " ".join(sorted(msvc.keys())))
  print("Windows SDK versions:", " ".join(sorted(sdk.keys())))
  exit(0)

msvc_ver = args.msvc_version or max(sorted(msvc.keys()))
sdk_ver = args.sdk_version or max(sorted(sdk.keys()))

if msvc_ver in msvc:
  msvc_pid = msvc[msvc_ver]
  msvc_ver = ".".join(msvc_pid.split(".")[4:-2])
else:
  exit(f"Unknown MSVC version: f{args.msvc_version}")

if sdk_ver in sdk:
  sdk_pid = sdk[sdk_ver]
else:
  exit(f"Unknown Windows SDK version: f{args.sdk_version}")

print(f"Downloading MSVC v{msvc_ver} and Windows SDK v{sdk_ver}")


### agree to license

tools = first(manifest["channelItems"], lambda x: x["id"] == "Microsoft.VisualStudio.Product.BuildTools")
resource = first(tools["localizedResources"], lambda x: x["language"] == "en-us")
license = resource["license"]

if not args.accept_license:
  accept = input(f"Do you accept Visual Studio license at {license} [Y/N] ? ")
  if not accept or accept[0].lower() != "y":
    exit(0)

OUTPUT.mkdir(exist_ok=True)
DOWNLOADS.mkdir(exist_ok=True)


### download MSVC

msvc_packages = [
  f"microsoft.visualcpp.dia.sdk",
  f"microsoft.vc.{msvc_ver}.crt.headers.base",
  f"microsoft.vc.{msvc_ver}.crt.source.base",
  f"microsoft.vc.{msvc_ver}.asan.headers.base",
  f"microsoft.vc.{msvc_ver}.pgo.headers.base",
]

for target in targets:
  msvc_packages += [
    f"microsoft.vc.{msvc_ver}.tools.host{host}.target{target}.base",
    f"microsoft.vc.{msvc_ver}.tools.host{host}.target{target}.res.base",
    f"microsoft.vc.{msvc_ver}.crt.{target}.desktop.base",
    f"microsoft.vc.{msvc_ver}.crt.{target}.store.base",
    f"microsoft.vc.{msvc_ver}.premium.tools.host{host}.target{target}.base",
    f"microsoft.vc.{msvc_ver}.pgo.{target}.base",
  ]
  if target in ["x86", "x64"]:
    msvc_packages += [f"microsoft.vc.{msvc_ver}.asan.{target}.base"]

  redist_suffix = ".onecore.desktop" if target == "arm" else ""
  redist_pkg = f"microsoft.vc.{msvc_ver}.crt.redist.{target}{redist_suffix}.base"
  if redist_pkg not in packages:
    redist_name = f"microsoft.visualcpp.crt.redist.{target}{redist_suffix}"
    redist = first(packages[redist_name])
    redist_pkg = first(redist["dependencies"], lambda dep: dep.endswith(".base")).lower()
  msvc_packages += [redist_pkg]

for pkg in sorted(msvc_packages):
  if pkg not in packages:
    print(f"\r{pkg} ... !!! MISSING !!!")
    continue
  p = first(packages[pkg], lambda p: p.get("language") in (None, "en-US"))
  for payload in p["payloads"]:
    filename = payload["fileName"]
    download_progress(payload["url"], payload["sha256"], filename)
    with zipfile.ZipFile(DOWNLOADS / filename) as z:
      for name in z.namelist():
        if name.startswith("Contents/"):
          out = OUTPUT / Path(name).relative_to("Contents")
          out.parent.mkdir(parents=True, exist_ok=True)
          out.write_bytes(z.read(name))


### download Windows SDK

sdk_packages = [
  f"Windows SDK for Windows Store Apps Tools-x86_en-us.msi",
  f"Windows SDK for Windows Store Apps Headers-x86_en-us.msi",
  f"Windows SDK for Windows Store Apps Headers OnecoreUap-x86_en-us.msi",
  f"Windows SDK for Windows Store Apps Libs-x86_en-us.msi",
  f"Universal CRT Headers Libraries and Sources-x86_en-us.msi",
]

for target in ALL_TARGETS:
  sdk_packages += [
    f"Windows SDK Desktop Headers {target}-x86_en-us.msi",
    f"Windows SDK OnecoreUap Headers {target}-x86_en-us.msi",
  ]

for target in targets:
  sdk_packages += [f"Windows SDK Desktop Libs {target}-x86_en-us.msi"]

with tempfile.TemporaryDirectory(dir=DOWNLOADS) as d:
  dst = Path(d)

  sdk_pkg = packages[sdk_pid][0]
  sdk_pkg = packages[first(sdk_pkg["dependencies"]).lower()][0]

  msi = []
  cabs = []

  # download msi files
  for pkg in sorted(sdk_packages):
    payload = first(sdk_pkg["payloads"], lambda p: p["fileName"] == f"Installers\\{pkg}")
    if payload is None:
      continue
    msi.append(DOWNLOADS / pkg)
    data = download_progress(payload["url"], payload["sha256"], pkg)
    cabs += list(get_msi_cabs(data))

  # download .cab files
  for pkg in cabs:
    payload = first(sdk_pkg["payloads"], lambda p: p["fileName"] == f"Installers\\{pkg}")
    download_progress(payload["url"], payload["sha256"], pkg)

  print("Unpacking msi files...")

  # run msi installers
  for m in msi:
    subprocess.check_call(["msiexec.exe", "/a", m, "/quiet", "/qn", f"TARGETDIR={OUTPUT.resolve()}"])
    (OUTPUT / m.name).unlink()


### versions

msvcv = first((OUTPUT / "VC/Tools/MSVC").glob("*")).name
sdkv = first((OUTPUT / "Windows Kits/10/bin").glob("*")).name


# place debug CRT runtime files into MSVC bin folder (not what real Visual Studio installer does... but is reasonable)
# NOTE: these are Target architecture, not Host architecture binaries

redist = OUTPUT / "VC/Redist"

if redist.exists():
  redistv = first((redist / "MSVC").glob("*")).name
  src = redist / "MSVC" / redistv / "debug_nonredist"
  for target in targets:
    for f in (src / target).glob("**/*.dll"):
      dst = OUTPUT / "VC/Tools/MSVC" / msvcv / f"bin/Host{host}" / target
      f.replace(dst / f.name)

  shutil.rmtree(redist)


# copy msdia140.dll file into MSVC bin folder
# NOTE: this is meant only for development - always Host architecture, even when placed into all Target architecture folders

msdia140dll = {
  "x86": "msdia140.dll",
  "x64": "amd64/msdia140.dll",
  "arm": "arm/msdia140.dll",
  "arm64": "arm64/msdia140.dll",
}

dst = OUTPUT / "VC/Tools/MSVC" / msvcv / f"bin/Host{host}"
src = OUTPUT / "DIA%20SDK/bin" / msdia140dll[host]
for target in targets:
  shutil.copyfile(src, dst / target / src.name)

shutil.rmtree(OUTPUT / "DIA%20SDK")


### cleanup

shutil.rmtree(OUTPUT / "Common7", ignore_errors=True)
shutil.rmtree(OUTPUT / "VC/Tools/MSVC" / msvcv / "Auxiliary")
for target in targets:
  for f in [f"store", "uwp", "enclave", "onecore"]:
    shutil.rmtree(OUTPUT / "VC/Tools/MSVC" / msvcv / "lib" / target / f, ignore_errors=True)
  shutil.rmtree(OUTPUT / "VC/Tools/MSVC" / msvcv / f"bin/Host{host}" / target / "onecore", ignore_errors=True)
for f in ["Catalogs", "DesignTime", f"bin/{sdkv}/chpe", f"Lib/{sdkv}/ucrt_enclave"]:
  shutil.rmtree(OUTPUT / "Windows Kits/10" / f, ignore_errors=True)
for arch in ["x86", "x64", "arm", "arm64"]:
  if arch not in targets:
    shutil.rmtree(OUTPUT / "Windows Kits/10/Lib" / sdkv / "ucrt" / arch, ignore_errors=True)
    shutil.rmtree(OUTPUT / "Windows Kits/10/Lib" / sdkv / "um" / arch, ignore_errors=True)
  if arch != host:
    shutil.rmtree(OUTPUT / "VC/Tools/MSVC" / msvcv / f"bin/Host{arch}", ignore_errors=True)
    shutil.rmtree(OUTPUT / "Windows Kits/10/bin" / sdkv / arch, ignore_errors=True)

# executable that is collecting & sending telemetry every time cl/link runs
for target in targets:
  (OUTPUT / "VC/Tools/MSVC" / msvcv / f"bin/Host{host}/{target}/vctip.exe").unlink(missing_ok=True)


### setup.bat

for target in targets:

  SETUP = fr"""@echo off

set VSCMD_ARG_HOST_ARCH={host}
set VSCMD_ARG_TGT_ARCH={target}

set VCToolsVersion={msvcv}
set WindowsSDKVersion={sdkv}\

set VCToolsInstallDir=%~dp0VC\Tools\MSVC\{msvcv}\
set WindowsSdkBinPath=%~dp0Windows Kits\10\bin\

set PATH=%~dp0VC\Tools\MSVC\{msvcv}\bin\Host{host}\{target};%~dp0Windows Kits\10\bin\{sdkv}\{host};%~dp0Windows Kits\10\bin\{sdkv}\{host}\ucrt;%PATH%
set INCLUDE=%~dp0VC\Tools\MSVC\{msvcv}\include;%~dp0Windows Kits\10\Include\{sdkv}\ucrt;%~dp0Windows Kits\10\Include\{sdkv}\shared;%~dp0Windows Kits\10\Include\{sdkv}\um;%~dp0Windows Kits\10\Include\{sdkv}\winrt;%~dp0Windows Kits\10\Include\{sdkv}\cppwinrt
set LIB=%~dp0VC\Tools\MSVC\{msvcv}\lib\{target};%~dp0Windows Kits\10\Lib\{sdkv}\ucrt\{target};%~dp0Windows Kits\10\Lib\{sdkv}\um\{target}
"""
  (OUTPUT / f"setup_{target}.bat").write_text(SETUP)

print(f"Total downloaded: {total_download>>20} MB")
print("Done!")

I would suggest to not do wine for this. Instead use one of 3rd party msi extraction utilities that runs natively in linux. Like cabextract, or msiextract from msitools, or some other. Not sure which one works the best, have not tried them.

@mmozeiko
I tried msiextract and got it working with the following patch.
It creates a msvc directory that is 100% identical to one generated using msiexec on Windows.

patch

--- a/portable-msvc.py
+++ b/portable-msvc.py
@@ -278,12 +278,13 @@ with tempfile.TemporaryDirectory(dir=DOWNLOADS) as d:
 
   # run msi installers
   for m in msi:
-    subprocess.check_call(["msiexec.exe", "/a", m, "/quiet", "/qn", f"TARGETDIR={OUTPUT.resolve()}"])
-    (OUTPUT / m.name).unlink()
+    subprocess.check_call(["msiextract", m, "-C", OUTPUT.resolve()])
 
 
 ### versions
 
+os.rename(OUTPUT / "Program Files/Windows Kits", OUTPUT / "Windows Kits")
+
 msvcv = first((OUTPUT / "VC/Tools/MSVC").glob("*")).name
 sdkv = first((OUTPUT / "Windows Kits/10/bin").glob("*")).name
 

(OUTPUT / m.name).unlink() was always throwing a FileNotFoundError, so I removed it. Not sure how to handle that.

With those changes, I can build a simple "Hello World" application :)

edit: As soon as I use the Windows SDK, it fails to link
edit2: It fails with the same link errors on a Windows system, so it's nothing Linux/wine-specific

How to install the python program in the first place? newest python version are not compatible with Windows 7 :(

you can't use official python installer, unfortunately....
but, there is a golden recipe: https://github.com/adang1345/PythonWin7

I'm using those builds already for years - works like a charm! highly recommended for old-schoolers :)

Thanks for the link! I'll try it :)

I get this error after the last update:

A:\BuildTools\Windows Kits\10\Include\10.0.26100.0\um\shobjidl_core.h(1911): fatal error C1083: Cannot open include file: 'ObjectArray.h': No such file or directory

Is that header file phyiscally preset on your disk?
in my case (older SDK) it's over here: "c:\Program Files (x86)\Windows Kits\10\Include\10.0.20348.0\um\ObjectArray.h"

No, it's missing, i'm on x64 target btw

I'm also, but using Win7

hi @mmozeiko
i have been thinking about this for quite some time now. would u mind creating a dedicated repo for this?

there are some merge requests i want to create, and i also think that this gist clearly has surpassed the use case and audience reach of a gist, and is now much more akin to a proper repo.

thanks a lot for all the work u have put into this.

What kind of merge requests are we talking about? I consider this script pretty much finished, and I'm ok only with keeping up with bugfixes and changes for newer versions of VS. I do not really want to turn this script into full fledged VS installation manager. VS build tools exe is meant for that.

Will this script ever be compatible with vcpkg?

hi! no, i am not talking about any big picture changes or making it into installer or whatever... my main motive is to smoothen up several of the rough edges the current version has, and make it more maintainable. just refactoring existing code.

is this script working in headless mode? I tried to install it through msys2 ssh, but somehow it stuck on unpacking msi

# python.exe portable-msvc.py
Downloading MSVC v14.41.17.11 and Windows SDK v26100
Do you accept Visual Studio license at https://go.microsoft.com/fwlink/?LinkId=2179911 [Y/N] ? Y
Microsoft.VC.14.40.17.10.CRT.Redist.X64.base.vsix ... 100%
Microsoft.VC.14.41.17.11.ASAN.Headers.base.vsix ... 100%
Microsoft.VC.14.41.17.11.ASAN.X64.base.vsix ... 100%
Microsoft.VC.14.41.17.11.CRT.Headers.base.vsix ... 100%
Microsoft.VC.14.41.17.11.CRT.Source.base.vsix ... 100%
Microsoft.VC.14.41.17.11.CRT.x64.Desktop.base.vsix ... 100%
Microsoft.VC.14.41.17.11.CRT.x64.Store.base.vsix ... 100%
Microsoft.VC.14.41.17.11.PGO.Headers.base.vsix ... 100%
Microsoft.VC.14.41.17.11.PGO.X64.base.vsix ... 100%
Microsoft.VC.14.41.17.11.Premium.Tools.HostX64.TargetX64.base.vsix ... 100%
Microsoft.VC.14.41.17.11.Tools.HostX64.TargetX64.base.vsix ... 100%
Microsoft.VC.14.41.17.11.Tools.HostX64.TargetX64.Res.base.enu.vsix ... 100%
Microsoft.VisualCpp.DIA.SDK.vsix ... 100%
Universal CRT Headers Libraries and Sources-x86_en-us.msi ... 100%
Windows SDK Desktop Headers arm64-x86_en-us.msi ... 100%
Windows SDK Desktop Headers x64-x86_en-us.msi ... 100%
Windows SDK Desktop Headers x86-x86_en-us.msi ... 100%
Windows SDK Desktop Libs x64-x86_en-us.msi ... 100%
Windows SDK OnecoreUap Headers arm64-x86_en-us.msi ... 100%
Windows SDK OnecoreUap Headers x64-x86_en-us.msi ... 100%
Windows SDK OnecoreUap Headers x86-x86_en-us.msi ... 100%
Windows SDK for Windows Store Apps Headers OnecoreUap-x86_en-us.msi ... 100%
Windows SDK for Windows Store Apps Headers-x86_en-us.msi ... 100%
Windows SDK for Windows Store Apps Libs-x86_en-us.msi ... 100%
Windows SDK for Windows Store Apps Tools-x86_en-us.msi ... 100%
16ab2ea2187acffa6435e334796c8c89.cab ... 100%
6ee7bbee8435130a869cf971694fd9e2.cab ... 100%
78fa3c824c2c48bd4a49ab5969adaaf7.cab ... 100%
7afc7b670accd8e3cc94cfffd516f5cb.cab ... 100%
96076045170fe5db6d5dcf14b6f6688e.cab ... 100%
a1e2a83aa8a71c48c742eeaff6e71928.cab ... 100%
b2f03f34ff83ec013b9e45c7cd8e8a73.cab ... 100%
beb5360d2daaa3167dea7ad16c28f996.cab ... 100%
d95da93904819b1f7e68adb98b49a9c7.cab ... 100%
eca0aa33de85194cd50ed6e0aae0156f.cab ... 100%
f9ff50431335056fb4fbac05b8268204.cab ... 100%
d1de88680a8e53fe75e01e94dc0ed767.cab ... 100%
07a57cdb41ba28cced14005f087267be.cab ... 100%
2e876dd22fa5e6785f137e3422dd50ec.cab ... 100%
4fe4c8b88812f5339018c0eef95acdb9.cab ... 100%
58314d0646d7e1a25e97c902166c3155.cab ... 100%
43fd989a0684600a8c4dda7a6373eb59.cab ... 100%
b0656253ef2f688d2982eafa2e73f621.cab ... 100%
f2e05dfd38ed343d3de77209cf3ecdae.cab ... 100%
e89e3dcbb016928c7e426238337d69eb.cab ... 100%
766c0ffd568bbb31bf7fb6793383e24a.cab ... 100%
8125ee239710f33ea485965f76fae646.cab ... 100%
c0aa6d435b0851bf34365aadabd0c20f.cab ... 100%
05047a45609f311645eebcac2739fc4c.cab ... 100%
13d68b8a7b6678a368e2d13ff4027521.cab ... 100%
463ad1b0783ebda908fd6c16a4abfe93.cab ... 100%
5a22e5cde814b041749fb271547f4dd5.cab ... 100%
e10768bb6e9d0ea730280336b697da66.cab ... 100%
f9b24c8280986c0683fbceca5326d806.cab ... 100%
2630bae9681db6a9f6722366f47d055c.cab ... 100%
26ea25236f12b23db661acf268a70cfa.cab ... 100%
2a30b5d1115d515c6ddd8cd6b5173835.cab ... 100%
4a4c678668584fc994ead5b99ccf7f03.cab ... 100%
61d57a7a82309cd161a854a6f4619e52.cab ... 100%
68de71e3e2fb9941ee5b7c77500c0508.cab ... 100%
69661e20556b3ca9456b946c2c881ddd.cab ... 100%
b82881a61b7477bd4eb5de2cd5037fe2.cab ... 100%
dcfb1aa345e349091a44e86ce1766566.cab ... 100%
e3d1b35aecfccda1b4af6fe5988ac4be.cab ... 100%
Unpacking msi files...

I do not know about msys2 ssh, but I have used it over regular Windows native ssh session - and there it works fine.

in the ssh, it not show error, maybe it stuck because the program trying to spawn some window popup?

when I access it directly and not from ssh connection, it show help popup and when I close it, the program show some error:

Unpacking msi files...
Traceback (most recent call last):
  File "/home/ACER/portable-msvc.py", line 285, in <module>
    subprocess.check_call(["msiexec.exe", "/a", m, "/quiet", "/qn", f"TARGETDIR={OUTPUT.resolve()}"])
  File "/usr/lib/python3.12/subprocess.py", line 413, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['msiexec.exe', '/a', PosixPath('downloads/Universal CRT Headers Libraries and Sources-x86_en-us.msi'), '/quiet', '/qn', 'TARGETDIR=/home/ACER/msvc']' returned non-zero exit status 103.

Hmmm it's weird the program show help popup knowing the /qn and /quiet option already passed to the msiexec

I think it's an issue of msys, but tried on powershell:

and it seems not an issue of msys

the script is in the latest version:

ACER@LAPTOP MSYS ~
$  sha256sum.exe portable-msvc.py
da47e39afb4e8f757bbd036171ef7295534b06bcdfa40004c5b2befc715ae389 *portable-msvc.py

ACER@LAPTOP MSYS ~
$  curl -o latest-version.py -L "https://gist.githubusercontent.com/mmozeiko/7f3162ec2988e81e56d5c4e22cde9977/raw/9f8555326867d4ecba70ee07f105f159f5d8afd5/portable-msvc.py"
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 12625  100 12625    0     0   1215      0  0:00:10  0:00:10 --:--:--  3036

ACER@LAPTOP MSYS ~
$  sha256sum.exe latest-version.py
da47e39afb4e8f757bbd036171ef7295534b06bcdfa40004c5b2befc715ae389 *latest-version.py

I think the error in msys2 happens because you are using msys python.exe, not Windows native one. The msys2 python resolves paths to msys2 paths - you can see it tries to unpack installation into /home/ACER/msvc folder, but Windows does not know what is /home/... path. It needs native path - like C:\Users\whatever\...

Try to execute it with native python, do not use msys2 python executable.

I'm not sure why it is showing UI, but can try adding extra arguments for logging - /log and C:\some\folder\log.txt. Then examine log file when UI is shown, maybe it will explain what is wrong.

after looking at the documentation about error code, I found it's ERROR_TOO_MANY_SEM_REQUESTS? I'm not sure where I should look into the error code, whether it's a decimal or hexadecimal form?

EDIT: sorry I'm not notice your comment before posting this comment, will try your suggestion.

EDIT 2:
by the way after trial and error, I found that the UI prompt seems only occurs when executing the script on the msys2 terminal.
and it executed without error on powershell, no have idea why msiexec isn't reliable on msys2 environment.

so I ended up following your suggestion ^^

Hi @mmozeiko ,how to download/add a component "Microsoft.VisualStudio.Component.VC.Modules.x86.x64". Adding lines in msvc_packages did not work
f"microsoft.vc.{msvc_ver}.modules.x86.x64.base", or f"microsoft.vc.modules.x86.x64.base", ?

Some info, ex. files go into MSVC\14.39.33519\ifc\x64\Debug Release
set "IFCPATH=%MSVC_ROOT%\ifc\x64
(copied manually files from visual studio installer)

With import std.core instead of #include, main.cpp with some functions(array, string, vector, cout) builds in around 0.350s instead of 0.850s

I think it should be microsoft.visualcpp.ifc.{target}. But I've never used modules, so no idea if it'll work. I prefer to use precompiled headers instead.