From 3735a516402208720f5fd7d104b2b882d762d2a3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C5=99emek=20Vysok=C3=BD?= <premek.vysoky@microsoft.com>
Date: Wed, 7 Dec 2022 20:06:24 +0100
Subject: [PATCH] Add a script for reproing VMR synchronization failures
 locally (#15097)

---
 eng/vmr-sync.sh | 180 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 180 insertions(+)
 create mode 100644 eng/vmr-sync.sh

diff --git a/eng/vmr-sync.sh b/eng/vmr-sync.sh
new file mode 100644
index 000000000..f948ff503
--- /dev/null
+++ b/eng/vmr-sync.sh
@@ -0,0 +1,180 @@
+#!/bin/bash
+
+### This script helps to reproduce potential failures of the 'Synchronize dotnet/dotnet'
+### build step from the **VMR Source-Build** job locally.
+### The following scenario is assumed:
+### - There is a PR in dotnet/installer
+### - The PR is failing on the 'VMR Source-Build' job in the 'Synchronize dotnet/dotnet' step
+###
+### There are a few possible reasons but usually this happens because there is a mismatch between
+### source patches that are applied on top of the files that are being synchronized from repositories
+### into the 'dotnet/dotnet' repo and new changes in the repositories.
+### This manifests as the following error:
+###     fail: Failed to synchronize repo installer
+###           Failed to apply the patch for src/aspnetcore
+###           Exit code: 1
+###           Std err:
+###           error: patch failed: src/aspnetcore/eng/SourceBuild.props:55
+###           error: src/aspnetcore/eng/SourceBuild.props: patch does not apply
+###
+### where 'src/aspnetcore/eng/SourceBuild.props' would be the file that is being patched and new
+### changes to it are conflicting with the patch that is being applied.
+###
+### The whole process can be reproduced locally easily by running this script.
+### The patches are located in a folder in the 'dotnet/installer' repository.
+### At the moment of writing, the location is 'src/SourceBuild/tarball/patches' but to get
+### the up-to-date location, please see the 'patchesPath' property in
+### https://github.com/dotnet/dotnet/blob/main/src/source-mappings.json
+###
+### You will need to compare what is in the patch and what is in the file and fix the patch.
+###
+### The tooling that synchronizes the VMR will need to clone the various repositories.
+### It clones them into a temporary folder and re-uses them on future runs so it is advised
+### you dedicate a folder to this to speed up your re-runs.
+###
+### This script will synchronize the 'dotnet/dotnet' repo locally and let you inspect the changes.
+###
+### USAGE:
+###     ./vmr-sync.sh --tmp-dir "$HOME/repos/tmp"
+### Options:
+###   -t, --tmp, --tmp-dir PATH
+###       Required. Path to the temporary folder where repositories will be cloned
+###   -v, --vmr, --vmr-dir PATH
+###       Optional. Path to the dotnet/dotnet repository. When null, gets cloned to the temporary folder
+###   -b, --branch, --vmr-branch BRANCH_NAME
+###       Optional. Branch of the 'dotnet/dotnet' repo to synchronize to
+###       This should match the target branch of the PR, defaults to 'main'
+###   --debug
+###       Optional. Turns on the most verbose logging for the VMR tooling
+
+source="${BASH_SOURCE[0]}"
+
+# resolve $source until the file is no longer a symlink
+while [[ -h "$source" ]]; do
+  scriptroot="$( cd -P "$( dirname "$source" )" && pwd )"
+  source="$(readlink "$source")"
+  # if $source was a relative symlink, we need to resolve it relative to the path where the
+  # symlink file was located
+  [[ $source != /* ]] && source="$scriptroot/$source"
+done
+scriptroot="$( cd -P "$( dirname "$source" )" && pwd )"
+
+function print_help () {
+    sed -n '/^### /,/^$/p' "$source" | cut -b 5-
+}
+
+COLOR_RED=$(tput setaf 1 2>/dev/null || true)
+COLOR_CYAN=$(tput setaf 6 2>/dev/null || true)
+COLOR_CLEAR=$(tput sgr0 2>/dev/null || true)
+COLOR_RESET=uniquesearchablestring
+FAILURE_PREFIX='> '
+
+function fail () {
+  echo "${COLOR_RED}$FAILURE_PREFIX${1//${COLOR_RESET}/${COLOR_RED}}${COLOR_CLEAR}" >&2
+}
+
+function highlight () {
+  echo "${COLOR_CYAN}$FAILURE_PREFIX${1//${COLOR_RESET}/${COLOR_CYAN}}${COLOR_CLEAR}"
+}
+
+installer_dir="$scriptroot/../"
+tmp_dir=''
+vmr_dir=''
+vmr_branch='main'
+verbosity=verbose
+# hashed name coming from the VMR tooling
+INSTALLER_TMP_DIR_NAME='03298978DFFFCD23'
+
+while [[ $# -gt 0 ]]; do
+  opt="$(echo "$1" | tr "[:upper:]" "[:lower:]")"
+  case "$opt" in
+    -t|--tmp|--tmp-dir)
+      tmp_dir=$2
+      shift
+      ;;
+    -v|--vmr|--vmr-dir)
+      vmr_dir=$2
+      shift
+      ;;
+    -b|--branch|--vmr-branch)
+      vmr_branch=$2
+      shift
+      ;;
+    -d|--debug)
+      verbosity=debug
+      ;;
+    -h|--help)
+      print_help
+      exit 0
+      ;;
+    *)
+      fail "Invalid argument: $1"
+      usage
+      exit 1
+      ;;
+  esac
+
+  shift
+done
+
+if [[ ! -d "$installer_dir" ]]; then
+  fail "Directory '$installer_dir' does not exist. Please specify the path to the dotnet/installer repo"
+  exit 1
+fi
+
+if [[ -z "$tmp_dir" ]]; then
+  fail "Missing --tmp-dir argument. Please specify the path to the temporary folder where the repositories will be cloned"
+  exit 1
+fi
+
+if [[ -z "$vmr_dir" ]]; then
+  vmr_dir="$tmp_dir/dotnet"
+fi
+
+if [[ ! -d "$tmp_dir" ]]; then
+  mkdir -p "$tmp_dir"
+fi
+
+if [[ ! -d "$vmr_dir" ]]; then
+  highlight "Cloning 'dotnet/dotnet' into $vmr_dir.."
+  git clone https://github.com/dotnet/dotnet "$vmr_dir"
+else
+  if ! git -C "$vmr_dir" diff --quiet; then
+    fail "There are changes in the working tree of $vmr_dir. Please commit or stash your changes"
+    exit 1
+  fi
+
+  highlight "Preparing $vmr_dir"
+  git -C "$vmr_dir" checkout "$vmr_branch"
+  git -C "$vmr_dir" pull
+fi
+
+set -e
+
+# These lines makes sure the temp dir (which the tooling would clone)
+# has the synchronized commit inside as well
+highlight 'Preparing the temporary directory..'
+rm -rf "${tmp_dir:?}/$INSTALLER_TMP_DIR_NAME"
+git clone "$installer_dir" "${tmp_dir:?}/$INSTALLER_TMP_DIR_NAME"
+
+# Prepare darc
+highlight 'Installing .NET, preparing the tooling..'
+source "$scriptroot/common/tools.sh"
+InitializeDotNetCli true
+dotnet="$scriptroot/../.dotnet/dotnet"
+"$dotnet" tool restore
+
+# Run the sync
+target_sha=$(git -C "$installer_dir" rev-parse HEAD)
+highlight "Starting the synchronization to $target_sha.."
+set +e
+
+if "$dotnet" darc vmr update --vmr "$vmr_dir" --tmp "$tmp_dir" --$verbosity --recursive installer:$target_sha; then
+  highlight "Synchronization succeeded"
+else
+  fail "Synchronization of dotnet/dotnet to $target_sha failed!"
+  fail "$vmr_dir is left in its last state (re-run of this script will reset it)."
+  fail "Please inspect the logs which contain path to the failing patch file (use --debug to get all the details)."
+  fail "Once you make changes to the conflicting VMR patch, commit it locally and re-run this script."
+  exit 1
+fi