.NET Installation Skill

Automated .NET SDK and runtime installation with intelligent platform detection, version management, and troubleshooting guidance.

Quick Start

Check Current Installation

dotnet --version
# Output: 8.0.100

dotnet --list-sdks
# Output: 8.0.100 [/usr/local/share/dotnet/sdk]

dotnet --list-runtimes
# Output: Microsoft.NETCore.App 8.0.0 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]

Platform Detection

The skill automatically detects your operating system and recommends the best installation method:

# Detected: macOS 14.2 (arm64)
# Recommended: Official installer package (.pkg)
# Alternative: Homebrew (brew install dotnet)

Quick Install (Recommended Methods)

Windows (WinGet):

# Install .NET 8 SDK (LTS)
winget install Microsoft.DotNet.SDK.8

# Verify installation
dotnet --version
# Output: 8.0.100

macOS (Official Installer):

# Download and install from:
# https://dotnet.microsoft.com/download/dotnet/8.0

# Or use Homebrew:
brew install dotnet

# Verify installation
dotnet --version
# Output: 8.0.100

Linux (Ubuntu/Debian):

# Add Microsoft package repository
wget https://packages.microsoft.com/config/ubuntu/22.04/packages-microsoft-prod.deb -O packages-microsoft-prod.deb
sudo dpkg -i packages-microsoft-prod.deb
rm packages-microsoft-prod.deb

# Install .NET 8 SDK
sudo apt-get update
sudo apt-get install -y dotnet-sdk-8.0

# Verify installation
dotnet --version
# Output: 8.0.100

SDK vs Runtime Decision

Install SDK when:

• Building applications
• Developing locally
• Running dotnet build or dotnet run
• Need the complete toolchain

Install Runtime only when:

• Deploying production apps
• Running pre-compiled applications
• Minimizing installation size
• Production servers

# Install SDK (includes runtime)
sudo apt-get install dotnet-sdk-8.0

# Install runtime only (smaller)
sudo apt-get install aspnetcore-runtime-8.0  # For ASP.NET Core apps
sudo apt-get install dotnet-runtime-8.0      # For console apps

Practical Guide

Windows Installation Methods

Method 1: WinGet (Recommended)

# List available .NET versions
winget search Microsoft.DotNet.SDK

# Install .NET 8 SDK (LTS)
winget install Microsoft.DotNet.SDK.8

# Install specific version
winget install Microsoft.DotNet.SDK.8 --version 8.0.100

# Update existing installation
winget upgrade Microsoft.DotNet.SDK.8

Method 2: Visual Studio Installer

# Visual Studio 2022 detected at: C:\Program Files\Visual Studio\2022\Community
# .NET 8 SDK available via: Modify Installation → .NET desktop development

Installation steps:

1. Launch Visual Studio Installer
2. Click "Modify" on your installation
3. Select ".NET desktop development" workload
4. Apply changes

Method 3: Standalone Installer

# Download: https://dotnet.microsoft.com/download/dotnet/8.0
# File: dotnet-sdk-8.0.100-win-x64.exe
# SHA512: [verification hash]

# Run installer (GUI)
.\dotnet-sdk-8.0.100-win-x64.exe

# Or silent install
.\dotnet-sdk-8.0.100-win-x64.exe /install /quiet /norestart

Method 4: PowerShell Script

# Download install script
Invoke-WebRequest -Uri https://dot.net/v1/dotnet-install.ps1 -OutFile dotnet-install.ps1

# Install latest .NET 8 SDK
.\dotnet-install.ps1 -Channel 8.0

# Install to custom location
.\dotnet-install.ps1 -Channel 8.0 -InstallDir "C:\Program Files\dotnet"

# Install runtime only
.\dotnet-install.ps1 -Channel 8.0 -Runtime dotnet

macOS Installation Methods

Method 1: Official Installer Package (Recommended)

# Detected: Apple Silicon (arm64)
# Recommended: dotnet-sdk-8.0.100-osx-arm64.pkg

# Download from: https://dotnet.microsoft.com/download/dotnet/8.0
# Double-click .pkg file to install

# Verify installation location
which dotnet
# Output: /usr/local/share/dotnet/dotnet

Method 2: Homebrew

# Install Homebrew (if needed)
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

# Install .NET SDK
brew install dotnet

# Install specific version (if available)
brew install dotnet@8

# Update existing installation
brew upgrade dotnet

Method 3: Install Script

# Download install script
curl -sSL https://dot.net/v1/dotnet-install.sh -o dotnet-install.sh
chmod +x dotnet-install.sh

# Install latest .NET 8 SDK
./dotnet-install.sh --channel 8.0

# Install to custom location
./dotnet-install.sh --channel 8.0 --install-dir ~/.dotnet

# Add to PATH
echo 'export PATH="$HOME/.dotnet:$PATH"' >> ~/.zshrc
source ~/.zshrc

Linux Installation Methods

Ubuntu/Debian

# Ubuntu 22.04 LTS
wget https://packages.microsoft.com/config/ubuntu/22.04/packages-microsoft-prod.deb -O packages-microsoft-prod.deb
sudo dpkg -i packages-microsoft-prod.deb
rm packages-microsoft-prod.deb

# Ubuntu 20.04 LTS
wget https://packages.microsoft.com/config/ubuntu/20.04/packages-microsoft-prod.deb -O packages-microsoft-prod.deb
sudo dpkg -i packages-microsoft-prod.deb
rm packages-microsoft-prod.deb

# Install SDK
sudo apt-get update
sudo apt-get install -y dotnet-sdk-8.0

# Install runtime only
sudo apt-get install -y aspnetcore-runtime-8.0

Fedora/RHEL/CentOS

# Fedora 39
sudo dnf install dotnet-sdk-8.0

# RHEL/CentOS (register Microsoft repository first)
sudo dnf install https://packages.microsoft.com/config/rhel/9/packages-microsoft-prod.rpm
sudo dnf install dotnet-sdk-8.0

Arch Linux

# Install from official repositories
sudo pacman -S dotnet-sdk

# Install runtime only
sudo pacman -S aspnet-runtime

Alpine Linux

# Add Microsoft repository
wget https://dot.net/v1/dotnet-install.sh
chmod +x dotnet-install.sh

# Install .NET 8
./dotnet-install.sh --channel 8.0 --install-dir /usr/share/dotnet

# Add to PATH
export PATH="$PATH:/usr/share/dotnet"

Version Management with global.json

Control which .NET SDK version your project uses:

# Create global.json for .NET 8
dotnet new globaljson --sdk-version 8.0.100

# View current global.json
cat global.json

{
  "sdk": {
    "version": "8.0.100",
    "rollForward": "latestPatch"
  }
}

Roll-forward policies:

• latestPatch - Use latest patch (8.0.x)
• latestFeature - Use latest feature band (8.x.x)
• latestMinor - Use latest minor (x.x.x)
• disable - Exact version required

Deep Dive

SDK vs Runtime Architecture

SDK Components:

.NET SDK 8.0.100
├── Runtime (8.0.0)
├── Compiler (Roslyn)
├── CLI Tools (dotnet build, run, publish)
├── Templates (dotnet new)
└── MSBuild

Runtime-Only Components:

.NET Runtime 8.0.0
├── CoreCLR (execution engine)
├── Base Class Libraries
└── Framework assemblies

Size comparison:

• SDK: ~200-400 MB
• Runtime: ~50-150 MB

Installing Multiple Versions Side-by-Side

.NET supports multiple versions installed simultaneously:

# List all installed SDKs
dotnet --list-sdks
# Output:
# 6.0.420 [/usr/local/share/dotnet/sdk]
# 7.0.410 [/usr/local/share/dotnet/sdk]
# 8.0.100 [/usr/local/share/dotnet/sdk]

# Install additional versions
sudo apt-get install dotnet-sdk-7.0  # Adds to existing installation

# Project selects version via global.json
cd my-project
cat global.json
# { "sdk": { "version": "7.0.410" } }

dotnet --version
# Output: 7.0.410 (selected by global.json)

Offline Installation

For air-gapped environments or restricted networks:

Windows

# Download offline installer
# https://dotnet.microsoft.com/download/dotnet/8.0
# Select: x64 | Binaries

# Extract to destination
Expand-Archive dotnet-sdk-8.0.100-win-x64.zip -DestinationPath "C:\Program Files\dotnet"

# Add to PATH
$env:PATH = "C:\Program Files\dotnet;$env:PATH"
[Environment]::SetEnvironmentVariable("PATH", $env:PATH, "Machine")

Linux

# Download tarball
wget https://download.visualstudio.microsoft.com/download/pr/[hash]/dotnet-sdk-8.0.100-linux-x64.tar.gz

# Extract to system location
sudo mkdir -p /usr/local/share/dotnet
sudo tar -xzf dotnet-sdk-8.0.100-linux-x64.tar.gz -C /usr/local/share/dotnet

# Create symlink
sudo ln -s /usr/local/share/dotnet/dotnet /usr/local/bin/dotnet

Docker Installation

# Use official .NET SDK image
FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build
WORKDIR /app

# Copy and restore project
COPY *.csproj ./
RUN dotnet restore

# Build application
COPY . ./
RUN dotnet publish -c Release -o out

# Runtime image (smaller)
FROM mcr.microsoft.com/dotnet/aspnet:8.0
WORKDIR /app
COPY --from=build /app/out .
ENTRYPOINT ["dotnet", "MyApp.dll"]

Common Troubleshooting

PATH Not Updated

# Verify dotnet location
which dotnet  # macOS/Linux
where.exe dotnet  # Windows

# If not found, add to PATH manually:

# macOS/Linux (bash)
echo 'export PATH="$PATH:/usr/local/share/dotnet"' >> ~/.bashrc
source ~/.bashrc

# macOS (zsh)
echo 'export PATH="$PATH:/usr/local/share/dotnet"' >> ~/.zshrc
source ~/.zshrc

# Windows (PowerShell)
$env:PATH = "$env:PATH;C:\Program Files\dotnet"

SDK Not Found After Installation

# Check installation location
dotnet --info
# Look for "Base Path:" in output

# Register installation manually (Linux)
sudo ln -s /usr/local/share/dotnet/dotnet /usr/bin/dotnet

# Clear NuGet cache if corrupted
dotnet nuget locals all --clear

Version Conflicts

# Remove specific SDK version
sudo apt-get remove dotnet-sdk-7.0  # Linux
winget uninstall Microsoft.DotNet.SDK.7  # Windows

# Force project to use available SDK
# Edit global.json:
{
  "sdk": {
    "version": "8.0.100",
    "rollForward": "latestMinor"  # More permissive
  }
}

References

Comprehensive Details: See reference.md for:

• Complete platform-specific installation commands
• Advanced version management strategies
• Enterprise deployment patterns
• CI/CD integration examples
• Performance optimization tips

Official Documentation:

• .NET Installation Guide
• Download .NET
• SDK vs Runtime
• global.json Reference