Especially as a new user it is a much better experience to receive a proper help response to `-h`. Currently passing `-h` will cause some runtime error with the `git remote` error help being shown. Not very helpful. It doesn't hurt to be a bit more user friendly in this case.
		
			
				
	
	
		
			420 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			Bash
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			420 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			Bash
		
	
	
		
			Executable File
		
	
	
	
	
#! /usr/bin/env bash
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set -e -o pipefail
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url=
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rev=
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expHash=
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hashType=$NIX_HASH_ALGO
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deepClone=$NIX_PREFETCH_GIT_DEEP_CLONE
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leaveDotGit=$NIX_PREFETCH_GIT_LEAVE_DOT_GIT
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fetchSubmodules=
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builder=
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branchName=$NIX_PREFETCH_GIT_BRANCH_NAME
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# ENV params
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out=${out:-}
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http_proxy=${http_proxy:-}
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# populated by clone_user_rev()
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fullRev=
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humanReadableRev=
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commitDate=
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commitDateStrict8601=
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if test -n "$deepClone"; then
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    deepClone=true
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else
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    deepClone=false
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fi
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if test "$leaveDotGit" != 1; then
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    leaveDotGit=
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else
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    leaveDotGit=true
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fi
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usage(){
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    echo  >&2 "syntax: nix-prefetch-git [options] [URL [REVISION [EXPECTED-HASH]]]
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Options:
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      --out path      Path where the output would be stored.
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      --url url       Any url understood by 'git clone'.
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      --rev ref       Any sha1 or references (such as refs/heads/master)
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      --hash h        Expected hash.
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      --deepClone     Clone the entire repository.
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      --no-deepClone  Make a shallow clone of just the required ref.
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      --leave-dotGit  Keep the .git directories.
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      --fetch-submodules Fetch submodules.
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      --builder       Clone as fetchgit does, but url, rev, and out option are mandatory.
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      --quiet         Only print the final json summary.
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"
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    exit 1
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}
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argi=0
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argfun=""
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for arg; do
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    if test -z "$argfun"; then
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        case $arg in
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            --out) argfun=set_out;;
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            --url) argfun=set_url;;
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            --rev) argfun=set_rev;;
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            --hash) argfun=set_hashType;;
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            --branch-name) argfun=set_branchName;;
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            --deepClone) deepClone=true;;
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            --quiet) QUIET=true;;
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            --no-deepClone) deepClone=false;;
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            --leave-dotGit) leaveDotGit=true;;
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            --fetch-submodules) fetchSubmodules=true;;
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            --builder) builder=true;;
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            -h|--help) usage; exit;;
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            *)
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                : $((++argi))
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                case $argi in
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                    1) url=$arg;;
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                    2) rev=$arg;;
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                    3) expHash=$arg;;
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                    *) exit 1;;
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                esac
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                ;;
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        esac
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    else
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        case $argfun in
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            set_*)
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                var=${argfun#set_}
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                eval $var=$arg
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                ;;
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        esac
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        argfun=""
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    fi
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done
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if test -z "$url"; then
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    usage
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fi
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init_remote(){
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    local url=$1
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    git init
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    git remote add origin "$url"
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    ( [ -n "$http_proxy" ] && git config http.proxy "$http_proxy" ) || true
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}
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# Return the reference of an hash if it exists on the remote repository.
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ref_from_hash(){
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    local hash=$1
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    git ls-remote origin | sed -n "\,$hash\t, { s,\(.*\)\t\(.*\),\2,; p; q}"
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}
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# Return the hash of a reference if it exists on the remote repository.
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hash_from_ref(){
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    local ref=$1
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    git ls-remote origin | sed -n "\,\t$ref, { s,\(.*\)\t\(.*\),\1,; p; q}"
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}
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# Returns a name based on the url and reference
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#
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# This function needs to be in sync with nix's fetchgit implementation
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# of urlToName() to re-use the same nix store paths.
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url_to_name(){
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    local url=$1
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    local ref=$2
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    local base
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    base=$(basename "$url" .git | cut -d: -f2)
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    if [[ $ref =~ ^[a-z0-9]+$ ]]; then
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        echo "$base-${ref:0:7}"
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    else
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        echo "$base"
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    fi
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}
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# Fetch everything and checkout the right sha1
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checkout_hash(){
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    local hash="$1"
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    local ref="$2"
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    if test -z "$hash"; then
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        hash=$(hash_from_ref "$ref")
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    fi
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    git fetch -t ${builder:+--progress} origin || return 1
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    git checkout -b "$branchName" "$hash" || return 1
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}
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# Fetch only a branch/tag and checkout it.
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checkout_ref(){
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    local hash="$1"
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    local ref="$2"
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    if "$deepClone"; then
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        # The caller explicitly asked for a deep clone.  Deep clones
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        # allow "git describe" and similar tools to work.  See
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        # https://marc.info/?l=nix-dev&m=139641582514772
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        # for a discussion.
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        return 1
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    fi
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    if test -z "$ref"; then
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        ref=$(ref_from_hash "$hash")
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    fi
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    if test -n "$ref"; then
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        # --depth option is ignored on http repository.
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        git fetch ${builder:+--progress} --depth 1 origin +"$ref" || return 1
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        git checkout -b "$branchName" FETCH_HEAD || return 1
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    else
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        return 1
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    fi
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}
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# Update submodules
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init_submodules(){
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    # Add urls into .git/config file
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    git submodule init
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    # list submodule directories and their hashes
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    git submodule status |
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    while read -r l; do
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        local hash
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        local dir
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        local name
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        local url
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        # checkout each submodule
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        hash=$(echo "$l" | awk '{print $1}' | tr -d '-')
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        dir=$(echo "$l" | sed -n 's/^.[0-9a-f]\+ \(.*[^)]*\)\( (.*)\)\?$/\1/p')
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        name=$(
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            git config -f .gitmodules --get-regexp submodule\..*\.path |
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            sed -n "s,^\(.*\)\.path $dir\$,\\1,p")
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        url=$(git config --get "${name}.url")
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        clone "$dir" "$url" "$hash" ""
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    done
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}
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clone(){
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    local top=$PWD
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    local dir="$1"
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    local url="$2"
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    local hash="$3"
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    local ref="$4"
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    cd "$dir"
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    # Initialize the repository.
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    init_remote "$url"
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    # Download data from the repository.
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    checkout_ref "$hash" "$ref" ||
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    checkout_hash "$hash" "$ref" || (
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        echo 1>&2 "Unable to checkout $hash$ref from $url."
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        exit 1
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    )
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    # Checkout linked sources.
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    if test -n "$fetchSubmodules"; then
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        init_submodules
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    fi
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    if [ -z "$builder" ] && [ -f .topdeps ]; then
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        if tg help &>/dev/null; then
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            echo "populating TopGit branches..."
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            tg remote --populate origin
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        else
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            echo "WARNING: would populate TopGit branches but TopGit is not available" >&2
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            echo "WARNING: install TopGit to fix the problem" >&2
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        fi
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    fi
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    cd "$top"
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}
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# Remove all remote branches, remove tags not reachable from HEAD, do a full
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# repack and then garbage collect unreferenced objects.
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make_deterministic_repo(){
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    local repo="$1"
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    # run in sub-shell to not touch current working directory
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    (
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    cd "$repo"
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    # Remove files that contain timestamps or otherwise have non-deterministic
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    # properties.
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    rm -rf .git/logs/ .git/hooks/ .git/index .git/FETCH_HEAD .git/ORIG_HEAD \
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        .git/refs/remotes/origin/HEAD .git/config
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    # Remove all remote branches.
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    git branch -r | while read -r branch; do
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        git branch -rD "$branch" >&2
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    done
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    # Remove tags not reachable from HEAD. If we're exactly on a tag, don't
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    # delete it.
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    maybe_tag=$(git tag --points-at HEAD)
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    git tag --contains HEAD | while read -r tag; do
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        if [ "$tag" != "$maybe_tag" ]; then
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            git tag -d "$tag" >&2
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        fi
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    done
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    # Do a full repack. Must run single-threaded, or else we lose determinism.
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    git config pack.threads 1
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    git repack -A -d -f
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    rm -f .git/config
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    # Garbage collect unreferenced objects.
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    git gc --prune=all
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    )
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}
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_clone_user_rev() {
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    local dir="$1"
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    local url="$2"
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    local rev="${3:-HEAD}"
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    # Perform the checkout.
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    case "$rev" in
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        HEAD|refs/*)
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            clone "$dir" "$url" "" "$rev" 1>&2;;
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        *)
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            if test -z "$(echo "$rev" | tr -d 0123456789abcdef)"; then
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                clone "$dir" "$url" "$rev" "" 1>&2
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            else
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                # if revision is not hexadecimal it might be a tag
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                clone "$dir" "$url" "" "refs/tags/$rev" 1>&2
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            fi;;
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    esac
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    pushd "$dir" >/dev/null
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    fullRev=$( (git rev-parse "$rev" 2>/dev/null || git rev-parse "refs/heads/$branchName") | tail -n1)
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    humanReadableRev=$(git describe "$fullRev" 2> /dev/null || git describe --tags "$fullRev" 2> /dev/null || echo -- none --)
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    commitDate=$(git show -1 --no-patch --pretty=%ci "$fullRev")
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    commitDateStrict8601=$(git show -1 --no-patch --pretty=%cI "$fullRev")
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    popd >/dev/null
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    # Allow doing additional processing before .git removal
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    eval "$NIX_PREFETCH_GIT_CHECKOUT_HOOK"
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    if test -z "$leaveDotGit"; then
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        echo "removing \`.git'..." >&2
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        find "$dir" -name .git -print0 | xargs -0 rm -rf
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    else
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        find "$dir" -name .git | while read -r gitdir; do
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            make_deterministic_repo "$(readlink -f "$gitdir/..")"
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        done
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    fi
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}
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clone_user_rev() {
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    if ! test -n "$QUIET"; then
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        _clone_user_rev "$@"
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    else
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        errfile="$(mktemp "${TMPDIR:-/tmp}/git-checkout-err-XXXXXXXX")"
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        # shellcheck disable=SC2064
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        trap "rm -rf \"$errfile\"" EXIT
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        _clone_user_rev "$@" 2> "$errfile" || (
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            status="$?"
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            cat "$errfile" >&2
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            exit "$status"
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        )
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    fi
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}
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json_escape() {
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    local s="$1"
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    s="${s//\\/\\\\}" # \
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    s="${s//\"/\\\"}" # "
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    s="${s//^H/\\\b}" # \b (backspace)
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    s="${s//^L/\\\f}" # \f (form feed)
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    s="${s//
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/\\\n}" # \n (newline)
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    s="${s//^M/\\\r}" # \r (carriage return)
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    s="${s//   /\\t}" # \t (tab)
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    echo "$s"
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}
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print_results() {
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    hash="$1"
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    if ! test -n "$QUIET"; then
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        echo "" >&2
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        echo "git revision is $fullRev" >&2
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        if test -n "$finalPath"; then
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            echo "path is $finalPath" >&2
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        fi
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        echo "git human-readable version is $humanReadableRev" >&2
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        echo "Commit date is $commitDate" >&2
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        if test -n "$hash"; then
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            echo "hash is $hash" >&2
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        fi
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    fi
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    if test -n "$hash"; then
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        cat <<EOF
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{
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  "url": "$(json_escape "$url")",
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  "rev": "$(json_escape "$fullRev")",
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  "date": "$(json_escape "$commitDateStrict8601")",
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  "$(json_escape "$hashType")": "$(json_escape "$hash")",
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  "fetchSubmodules": $([[ -n "$fetchSubmodules" ]] && echo true || echo false)
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}
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EOF
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    fi
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}
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if test -z "$branchName"; then
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    branchName=fetchgit
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fi
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if test -n "$builder"; then
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    test -n "$out" -a -n "$url" -a -n "$rev" || usage
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    mkdir -p "$out"
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    clone_user_rev "$out" "$url" "$rev"
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else
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    if test -z "$hashType"; then
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        hashType=sha256
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    fi
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    # If the hash was given, a file with that hash may already be in the
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    # store.
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    if test -n "$expHash"; then
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        finalPath=$(nix-store --print-fixed-path --recursive "$hashType" "$expHash" "$(url_to_name "$url" "$rev")")
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        if ! nix-store --check-validity "$finalPath" 2> /dev/null; then
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            finalPath=
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        fi
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        hash=$expHash
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    fi
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						|
 | 
						|
    # If we don't know the hash or a path with that hash doesn't exist,
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    # download the file and add it to the store.
 | 
						|
    if test -z "$finalPath"; then
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 | 
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        tmpPath="$(mktemp -d "${TMPDIR:-/tmp}/git-checkout-tmp-XXXXXXXX")"
 | 
						|
        # shellcheck disable=SC2064
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        trap "rm -rf \"$tmpPath\"" EXIT
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 | 
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        tmpFile="$tmpPath/$(url_to_name "$url" "$rev")"
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        mkdir -p "$tmpFile"
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 | 
						|
        # Perform the checkout.
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        clone_user_rev "$tmpFile" "$url" "$rev"
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 | 
						|
        # Compute the hash.
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        hash=$(nix-hash --type $hashType --base32 "$tmpFile")
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 | 
						|
        # Add the downloaded file to the Nix store.
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        finalPath=$(nix-store --add-fixed --recursive "$hashType" "$tmpFile")
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						|
 | 
						|
        if test -n "$expHash" -a "$expHash" != "$hash"; then
 | 
						|
            echo "hash mismatch for URL \`$url'. Got \`$hash'; expected \`$expHash'." >&2
 | 
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            exit 1
 | 
						|
        fi
 | 
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    fi
 | 
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 | 
						|
    print_results "$hash"
 | 
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 | 
						|
    if test -n "$PRINT_PATH"; then
 | 
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        echo "$finalPath"
 | 
						|
    fi
 | 
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fi
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