nixpkgs/pkgs/stdenv/generic/setup.sh

932 lines
24 KiB
Bash
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

set -e
set -o pipefail
: ${outputs:=out}
######################################################################
# Hook handling.
# Run all hooks with the specified name in the order in which they
# were added, stopping if any fails (returns a non-zero exit
# code). The hooks for <hookName> are the shell function or variable
# <hookName>, and the values of the shell array <hookName>Hooks.
runHook() {
local hookName="$1"
shift
local var="$hookName"
if [[ "$hookName" =~ Hook$ ]]; then var+=s; else var+=Hooks; fi
eval "local -a dummy=(\"\${$var[@]}\")"
for hook in "_callImplicitHook 0 $hookName" "${dummy[@]}"; do
_eval "$hook" "$@"
done
return 0
}
# Run all hooks with the specified name, until one succeeds (returns a
# zero exit code). If none succeed, return a non-zero exit code.
runOneHook() {
local hookName="$1"
shift
local var="$hookName"
if [[ "$hookName" =~ Hook$ ]]; then var+=s; else var+=Hooks; fi
eval "local -a dummy=(\"\${$var[@]}\")"
for hook in "_callImplicitHook 1 $hookName" "${dummy[@]}"; do
if _eval "$hook" "$@"; then
return 0
fi
done
return 1
}
# Run the named hook, either by calling the function with that name or
# by evaluating the variable with that name. This allows convenient
# setting of hooks both from Nix expressions (as attributes /
# environment variables) and from shell scripts (as functions). If you
# want to allow multiple hooks, use runHook instead.
_callImplicitHook() {
local def="$1"
local hookName="$2"
case "$(type -t $hookName)" in
(function|alias|builtin) $hookName;;
(file) source $hookName;;
(keyword) :;;
(*) if [ -z "${!hookName}" ]; then return "$def"; else eval "${!hookName}"; fi;;
esac
}
# A function wrapper around eval that ensures that return inside
# hooks exits the hook, not the caller.
_eval() {
local code="$1"
shift
if [ "$(type -t $code)" = function ]; then
eval "$code \"\$@\""
else
eval "$code"
fi
}
######################################################################
# Logging.
nestingLevel=0
startNest() {
nestingLevel=$(($nestingLevel + 1))
echo -en "\033[$1p"
}
stopNest() {
nestingLevel=$(($nestingLevel - 1))
echo -en "\033[q"
}
header() {
startNest "$2"
echo "$1"
}
# Make sure that even when we exit abnormally, the original nesting
# level is properly restored.
closeNest() {
while [ $nestingLevel -gt 0 ]; do
stopNest
done
}
######################################################################
# Error handling.
exitHandler() {
exitCode=$?
set +e
closeNest
if [ -n "$showBuildStats" ]; then
times > "$NIX_BUILD_TOP/.times"
local -a times=($(cat "$NIX_BUILD_TOP/.times"))
# Print the following statistics:
# - user time for the shell
# - system time for the shell
# - user time for all child processes
# - system time for all child processes
echo "build time elapsed: " ${times[*]}
fi
if [ $exitCode != 0 ]; then
runHook failureHook
# If the builder had a non-zero exit code and
# $succeedOnFailure is set, create the file
# $out/nix-support/failed to signal failure, and exit
# normally. Otherwise, return the original exit code.
if [ -n "$succeedOnFailure" ]; then
echo "build failed with exit code $exitCode (ignored)"
mkdir -p "$out/nix-support"
printf "%s" $exitCode > "$out/nix-support/failed"
exit 0
fi
else
runHook exitHook
fi
exit $exitCode
}
trap "exitHandler" EXIT
######################################################################
# Helper functions.
addToSearchPathWithCustomDelimiter() {
local delimiter=$1
local varName=$2
local dir=$3
if [ -d "$dir" ]; then
eval export ${varName}=${!varName}${!varName:+$delimiter}${dir}
fi
}
PATH_DELIMITER=':'
addToSearchPath() {
addToSearchPathWithCustomDelimiter "${PATH_DELIMITER}" "$@"
}
ensureDir() {
echo "warning: ensureDir is deprecated; use mkdir instead" >&2
local dir
for dir in "$@"; do
if ! [ -x "$dir" ]; then mkdir -p "$dir"; fi
done
}
# Add $1/lib* into rpaths.
# The function is used in multiple-outputs.sh hook,
# so it is defined here but tried after the hook.
_addRpathPrefix() {
if [ "$NIX_NO_SELF_RPATH" != 1 ]; then
export NIX_LDFLAGS="-rpath $1/lib $NIX_LDFLAGS"
if [ -n "$NIX_LIB64_IN_SELF_RPATH" ]; then
export NIX_LDFLAGS="-rpath $1/lib64 $NIX_LDFLAGS"
fi
if [ -n "$NIX_LIB32_IN_SELF_RPATH" ]; then
export NIX_LDFLAGS="-rpath $1/lib32 $NIX_LDFLAGS"
fi
fi
}
# Return success if the specified file is an ELF object.
isELF() {
local fn="$1"
local magic
exec {fd}< "$fn"
read -n 4 -u $fd magic
exec {fd}<&-
if [[ "$magic" =~ ELF ]]; then return 0; else return 1; fi
}
# Return success if the specified file is a script (i.e. starts with
# "#!").
isScript() {
local fn="$1"
local magic
if ! [ -x /bin/sh ]; then return 0; fi
exec {fd}< "$fn"
read -n 2 -u $fd magic
exec {fd}<&-
if [[ "$magic" =~ \#! ]]; then return 0; else return 1; fi
}
######################################################################
# Initialisation.
# Set a fallback default value for SOURCE_DATE_EPOCH, used by some
# build tools to provide a deterministic substitute for the "current"
# time. Note that 1 = 1970-01-01 00:00:01. We don't use 0 because it
# confuses some applications.
export SOURCE_DATE_EPOCH
: ${SOURCE_DATE_EPOCH:=1}
# Wildcard expansions that don't match should expand to an empty list.
# This ensures that, for instance, "for i in *; do ...; done" does the
# right thing.
shopt -s nullglob
# Set up the initial path.
PATH=
for i in $initialPath; do
if [ "$i" = / ]; then i=; fi
addToSearchPath PATH $i/bin
done
if [ "$NIX_DEBUG" = 1 ]; then
echo "initial path: $PATH"
fi
# Check that the pre-hook initialised SHELL.
if [ -z "$SHELL" ]; then echo "SHELL not set"; exit 1; fi
BASH="$SHELL"
export CONFIG_SHELL="$SHELL"
# Dummy implementation of the paxmark function. On Linux, this is
# overwritten by paxctl's setup hook.
paxmark() { true; }
# Execute the pre-hook.
if [ -z "$shell" ]; then export shell=$SHELL; fi
runHook preHook
# Allow the caller to augment buildInputs (it's not always possible to
# do this before the call to setup.sh, since the PATH is empty at that
# point; here we have a basic Unix environment).
runHook addInputsHook
# Recursively find all build inputs.
findInputs() {
local pkg="$1"
local var=$2
local propagatedBuildInputsFile=$3
case ${!var} in
*\ $pkg\ *)
return 0
;;
esac
eval $var="'${!var} $pkg '"
if ! [ -e "$pkg" ]; then
echo "build input $pkg does not exist" >&2
exit 1
fi
if [ -f "$pkg" ]; then
source "$pkg"
fi
if [ -d $1/bin ]; then
addToSearchPath _PATH $1/bin
fi
if [ -f "$pkg/nix-support/setup-hook" ]; then
source "$pkg/nix-support/setup-hook"
fi
if [ -f "$pkg/nix-support/$propagatedBuildInputsFile" ]; then
for i in $(cat "$pkg/nix-support/$propagatedBuildInputsFile"); do
findInputs "$i" $var $propagatedBuildInputsFile
done
fi
}
if [ -z "$crossConfig" ]; then
# Not cross-compiling - both buildInputs (and variants like propagatedBuildInputs)
# are handled identically to nativeBuildInputs
nativePkgs=""
for i in $nativeBuildInputs $buildInputs \
$defaultNativeBuildInputs $defaultBuildInputs \
$propagatedNativeBuildInputs $propagatedBuildInputs; do
findInputs $i nativePkgs propagated-native-build-inputs
done
else
crossPkgs=""
for i in $buildInputs $defaultBuildInputs $propagatedBuildInputs; do
findInputs $i crossPkgs propagated-build-inputs
done
nativePkgs=""
for i in $nativeBuildInputs $defaultNativeBuildInputs $propagatedNativeBuildInputs; do
findInputs $i nativePkgs propagated-native-build-inputs
done
fi
# Set the relevant environment variables to point to the build inputs
# found above.
_addToNativeEnv() {
local pkg=$1
# Run the package-specific hooks set by the setup-hook scripts.
runHook envHook "$pkg"
}
for i in $nativePkgs; do
_addToNativeEnv $i
done
_addToCrossEnv() {
local pkg=$1
# Run the package-specific hooks set by the setup-hook scripts.
runHook crossEnvHook "$pkg"
}
for i in $crossPkgs; do
_addToCrossEnv $i
done
_addRpathPrefix "$out"
# Set the TZ (timezone) environment variable, otherwise commands like
# `date' will complain (e.g., `Tue Mar 9 10:01:47 Local time zone must
# be set--see zic manual page 2004').
export TZ=UTC
# Set the prefix. This is generally $out, but it can be overriden,
# for instance if we just want to perform a test build/install to a
# temporary location and write a build report to $out.
if [ -z "$prefix" ]; then
prefix="$out";
fi
if [ "$useTempPrefix" = 1 ]; then
prefix="$NIX_BUILD_TOP/tmp_prefix";
fi
PATH=$_PATH${_PATH:+:}$PATH
if [ "$NIX_DEBUG" = 1 ]; then
echo "final path: $PATH"
fi
# Make GNU Make produce nested output.
export NIX_INDENT_MAKE=1
# Normalize the NIX_BUILD_CORES variable. The value might be 0, which
# means that we're supposed to try and auto-detect the number of
# available CPU cores at run-time.
if [ -z "${NIX_BUILD_CORES:-}" ]; then
NIX_BUILD_CORES="1"
elif [ "$NIX_BUILD_CORES" -le 0 ]; then
NIX_BUILD_CORES=$(nproc 2>/dev/null || true)
if expr >/dev/null 2>&1 "$NIX_BUILD_CORES" : "^[0-9][0-9]*$"; then
:
else
NIX_BUILD_CORES="1"
fi
fi
export NIX_BUILD_CORES
# Prevent OpenSSL-based applications from using certificates in
# /etc/ssl.
# Leave it in shells for convenience.
if [ -z "$SSL_CERT_FILE" ] && [ -z "$IN_NIX_SHELL" ]; then
export SSL_CERT_FILE=/no-cert-file.crt
fi
######################################################################
# Textual substitution functions.
substitute() {
local input="$1"
local output="$2"
if [ ! -f "$input" ]; then
echo "substitute(): file '$input' does not exist"
return 1
fi
local -a params=("$@")
local n p pattern replacement varName content
# a slightly hacky way to keep newline at the end
content="$(cat "$input"; printf "%s" X)"
content="${content%X}"
for ((n = 2; n < ${#params[*]}; n += 1)); do
p="${params[$n]}"
if [ "$p" = --replace ]; then
pattern="${params[$((n + 1))]}"
replacement="${params[$((n + 2))]}"
n=$((n + 2))
fi
if [ "$p" = --subst-var ]; then
varName="${params[$((n + 1))]}"
n=$((n + 1))
# check if the used nix attribute name is a valid bash name
if ! [[ "$varName" =~ ^[a-zA-Z_][a-zA-Z0-9_]*$ ]]; then
echo "WARNING: substitution variables should be valid bash names,"
echo " \"$varName\" isn't and therefore was skipped; it might be caused"
echo " by multi-line phases in variables - see #14907 for details."
continue
fi
pattern="@$varName@"
replacement="${!varName}"
fi
if [ "$p" = --subst-var-by ]; then
pattern="@${params[$((n + 1))]}@"
replacement="${params[$((n + 2))]}"
n=$((n + 2))
fi
content="${content//"$pattern"/$replacement}"
done
if [ -e "$output" ]; then chmod +w "$output"; fi
printf "%s" "$content" > "$output"
}
substituteInPlace() {
local fileName="$1"
shift
substitute "$fileName" "$fileName" "$@"
}
# Substitute all environment variables that do not start with an upper-case
# character or underscore. Note: other names that aren't bash-valid
# will cause an error during `substitute --subst-var`.
substituteAll() {
local input="$1"
local output="$2"
local -a args=()
# Select all environment variables that start with a lowercase character.
for varName in $(env | sed -e $'s/^\([a-z][^= \t]*\)=.*/\\1/; t \n d'); do
if [ "$NIX_DEBUG" = "1" ]; then
echo "@${varName}@ -> '${!varName}'"
fi
args+=("--subst-var" "$varName")
done
substitute "$input" "$output" "${args[@]}"
}
substituteAllInPlace() {
local fileName="$1"
shift
substituteAll "$fileName" "$fileName" "$@"
}
######################################################################
# What follows is the generic builder.
# This function is useful for debugging broken Nix builds. It dumps
# all environment variables to a file `env-vars' in the build
# directory. If the build fails and the `-K' option is used, you can
# then go to the build directory and source in `env-vars' to reproduce
# the environment used for building.
dumpVars() {
if [ "$noDumpEnvVars" != 1 ]; then
export > "$NIX_BUILD_TOP/env-vars" || true
fi
}
# Utility function: echo the base name of the given path, with the
# prefix `HASH-' removed, if present.
stripHash() {
local strippedName="$(basename "$1")";
if echo "$strippedName" | grep -q '^[a-z0-9]\{32\}-'; then
echo "$strippedName" | cut -c34-
else
echo "$strippedName"
fi
}
unpackCmdHooks+=(_defaultUnpack)
_defaultUnpack() {
local fn="$1"
if [ -d "$fn" ]; then
# We can't preserve hardlinks because they may have been
# introduced by store optimization, which might break things
# in the build.
cp -pr --reflink=auto "$fn" "$(stripHash "$fn")"
else
case "$fn" in
*.tar.xz | *.tar.lzma)
# Don't rely on tar knowing about .xz.
xz -d < "$fn" | tar xf -
;;
*.tar | *.tar.* | *.tgz | *.tbz2)
# GNU tar can automatically select the decompression method
# (info "(tar) gzip").
tar xf "$fn"
;;
*)
return 1
;;
esac
fi
}
unpackFile() {
curSrc="$1"
header "unpacking source archive $curSrc" 3
if ! runOneHook unpackCmd "$curSrc"; then
echo "do not know how to unpack source archive $curSrc"
exit 1
fi
stopNest
}
unpackPhase() {
runHook preUnpack
if [ -z "$srcs" ]; then
if [ -z "$src" ]; then
echo 'variable $src or $srcs should point to the source'
exit 1
fi
srcs="$src"
fi
# To determine the source directory created by unpacking the
# source archives, we record the contents of the current
# directory, then look below which directory got added. Yeah,
# it's rather hacky.
local dirsBefore=""
for i in *; do
if [ -d "$i" ]; then
dirsBefore="$dirsBefore $i "
fi
done
# Unpack all source archives.
for i in $srcs; do
unpackFile $i
done
# Find the source directory.
if [ -n "$setSourceRoot" ]; then
runOneHook setSourceRoot
elif [ -z "$sourceRoot" ]; then
sourceRoot=
for i in *; do
if [ -d "$i" ]; then
case $dirsBefore in
*\ $i\ *)
;;
*)
if [ -n "$sourceRoot" ]; then
echo "unpacker produced multiple directories"
exit 1
fi
sourceRoot="$i"
;;
esac
fi
done
fi
if [ -z "$sourceRoot" ]; then
echo "unpacker appears to have produced no directories"
exit 1
fi
echo "source root is $sourceRoot"
# By default, add write permission to the sources. This is often
# necessary when sources have been copied from other store
# locations.
if [ "$dontMakeSourcesWritable" != 1 ]; then
chmod -R u+w "$sourceRoot"
fi
runHook postUnpack
}
patchPhase() {
runHook prePatch
for i in $patches; do
header "applying patch $i" 3
local uncompress=cat
case "$i" in
*.gz)
uncompress="gzip -d"
;;
*.bz2)
uncompress="bzip2 -d"
;;
*.xz)
uncompress="xz -d"
;;
*.lzma)
uncompress="lzma -d"
;;
esac
# "2>&1" is a hack to make patch fail if the decompressor fails (nonexistent patch, etc.)
$uncompress < "$i" 2>&1 | patch ${patchFlags:--p1}
stopNest
done
runHook postPatch
}
fixLibtool() {
sed -i -e 's^eval sys_lib_.*search_path=.*^^' "$1"
}
configurePhase() {
runHook preConfigure
if [ -z "$configureScript" -a -x ./configure ]; then
configureScript=./configure
fi
if [ -z "$dontFixLibtool" ]; then
find . -iname "ltmain.sh" | while read i; do
echo "fixing libtool script $i"
fixLibtool $i
done
fi
if [ -z "$dontAddPrefix" -a -n "$prefix" ]; then
configureFlags="${prefixKey:---prefix=}$prefix $configureFlags"
fi
# Add --disable-dependency-tracking to speed up some builds.
if [ -z "$dontAddDisableDepTrack" ]; then
if [ -f "$configureScript" ] && grep -q dependency-tracking "$configureScript"; then
configureFlags="--disable-dependency-tracking $configureFlags"
fi
fi
# By default, disable static builds.
if [ -z "$dontDisableStatic" ]; then
if [ -f "$configureScript" ] && grep -q enable-static "$configureScript"; then
configureFlags="--disable-static $configureFlags"
fi
fi
if [ -n "$configureScript" ]; then
echo "configure flags: $configureFlags ${configureFlagsArray[@]}"
$configureScript $configureFlags "${configureFlagsArray[@]}"
else
echo "no configure script, doing nothing"
fi
runHook postConfigure
}
buildPhase() {
runHook preBuild
if [ -z "$makeFlags" ] && ! [ -n "$makefile" -o -e "Makefile" -o -e "makefile" -o -e "GNUmakefile" ]; then
echo "no Makefile, doing nothing"
else
# See https://github.com/NixOS/nixpkgs/pull/1354#issuecomment-31260409
makeFlags="SHELL=$SHELL $makeFlags"
echo "make flags: $makeFlags ${makeFlagsArray[@]} $buildFlags ${buildFlagsArray[@]}"
make ${makefile:+-f $makefile} \
${enableParallelBuilding:+-j${NIX_BUILD_CORES} -l${NIX_BUILD_CORES}} \
$makeFlags "${makeFlagsArray[@]}" \
$buildFlags "${buildFlagsArray[@]}"
fi
runHook postBuild
}
checkPhase() {
runHook preCheck
echo "check flags: $makeFlags ${makeFlagsArray[@]} $checkFlags ${checkFlagsArray[@]}"
make ${makefile:+-f $makefile} \
${enableParallelBuilding:+-j${NIX_BUILD_CORES} -l${NIX_BUILD_CORES}} \
$makeFlags "${makeFlagsArray[@]}" \
${checkFlags:-VERBOSE=y} "${checkFlagsArray[@]}" ${checkTarget:-check}
runHook postCheck
}
installPhase() {
runHook preInstall
if [ -n "$prefix" ]; then
mkdir -p "$prefix"
fi
installTargets=${installTargets:-install}
echo "install flags: $installTargets $makeFlags ${makeFlagsArray[@]} $installFlags ${installFlagsArray[@]}"
make ${makefile:+-f $makefile} $installTargets \
$makeFlags "${makeFlagsArray[@]}" \
$installFlags "${installFlagsArray[@]}"
runHook postInstall
}
# The fixup phase performs generic, package-independent stuff, like
# stripping binaries, running patchelf and setting
# propagated-build-inputs.
fixupPhase() {
# Make sure everything is writable so "strip" et al. work.
for output in $outputs; do
if [ -e "${!output}" ]; then chmod -R u+w "${!output}"; fi
done
runHook preFixup
# Apply fixup to each output.
local output
for output in $outputs; do
prefix=${!output} runHook fixupOutput
done
# Propagate build inputs and setup hook into the development output.
if [ -z "$crossConfig" ]; then
# Not cross-compiling - propagatedBuildInputs are handled identically to propagatedNativeBuildInputs
local propagated="$propagatedNativeBuildInputs"
if [ -n "$propagatedBuildInputs" ]; then
propagated+="${propagated:+ }$propagatedBuildInputs"
fi
if [ -n "$propagated" ]; then
mkdir -p "${!outputDev}/nix-support"
echo "$propagated" > "${!outputDev}/nix-support/propagated-native-build-inputs"
fi
else
if [ -n "$propagatedBuildInputs" ]; then
mkdir -p "${!outputDev}/nix-support"
echo "$propagatedBuildInputs" > "${!outputDev}/nix-support/propagated-build-inputs"
fi
if [ -n "$propagatedNativeBuildInputs" ]; then
mkdir -p "${!outputDev}/nix-support"
echo "$propagatedNativeBuildInputs" > "${!outputDev}/nix-support/propagated-native-build-inputs"
fi
fi
if [ -n "$setupHook" ]; then
mkdir -p "${!outputDev}/nix-support"
substituteAll "$setupHook" "${!outputDev}/nix-support/setup-hook"
fi
# Propagate user-env packages into the output with binaries, TODO?
if [ -n "$propagatedUserEnvPkgs" ]; then
mkdir -p "${!outputBin}/nix-support"
echo "$propagatedUserEnvPkgs" > "${!outputBin}/nix-support/propagated-user-env-packages"
fi
runHook postFixup
}
installCheckPhase() {
runHook preInstallCheck
echo "installcheck flags: $makeFlags ${makeFlagsArray[@]} $installCheckFlags ${installCheckFlagsArray[@]}"
make ${makefile:+-f $makefile} \
${enableParallelBuilding:+-j${NIX_BUILD_CORES} -l${NIX_BUILD_CORES}} \
$makeFlags "${makeFlagsArray[@]}" \
$installCheckFlags "${installCheckFlagsArray[@]}" ${installCheckTarget:-installcheck}
runHook postInstallCheck
}
distPhase() {
runHook preDist
echo "dist flags: $distFlags ${distFlagsArray[@]}"
make ${makefile:+-f $makefile} $distFlags "${distFlagsArray[@]}" ${distTarget:-dist}
if [ "$dontCopyDist" != 1 ]; then
mkdir -p "$out/tarballs"
# Note: don't quote $tarballs, since we explicitly permit
# wildcards in there.
cp -pvd ${tarballs:-*.tar.gz} $out/tarballs
fi
runHook postDist
}
showPhaseHeader() {
local phase="$1"
case $phase in
unpackPhase) header "unpacking sources";;
patchPhase) header "patching sources";;
configurePhase) header "configuring";;
buildPhase) header "building";;
checkPhase) header "running tests";;
installPhase) header "installing";;
fixupPhase) header "post-installation fixup";;
installCheckPhase) header "running install tests";;
*) header "$phase";;
esac
}
genericBuild() {
if [ -f "$buildCommandPath" ]; then
. "$buildCommandPath"
return
fi
if [ -n "$buildCommand" ]; then
eval "$buildCommand"
return
fi
if [ -z "$phases" ]; then
phases="$prePhases unpackPhase patchPhase $preConfigurePhases \
configurePhase $preBuildPhases buildPhase checkPhase \
$preInstallPhases installPhase $preFixupPhases fixupPhase installCheckPhase \
$preDistPhases distPhase $postPhases";
fi
for curPhase in $phases; do
if [ "$curPhase" = buildPhase -a -n "$dontBuild" ]; then continue; fi
if [ "$curPhase" = checkPhase -a -z "$doCheck" ]; then continue; fi
if [ "$curPhase" = installPhase -a -n "$dontInstall" ]; then continue; fi
if [ "$curPhase" = fixupPhase -a -n "$dontFixup" ]; then continue; fi
if [ "$curPhase" = installCheckPhase -a -z "$doInstallCheck" ]; then continue; fi
if [ "$curPhase" = distPhase -a -z "$doDist" ]; then continue; fi
if [ -n "$tracePhases" ]; then
echo
echo "@ phase-started $out $curPhase"
fi
showPhaseHeader "$curPhase"
dumpVars
# Evaluate the variable named $curPhase if it exists, otherwise the
# function named $curPhase.
eval "${!curPhase:-$curPhase}"
if [ "$curPhase" = unpackPhase ]; then
cd "${sourceRoot:-.}"
fi
if [ -n "$tracePhases" ]; then
echo
echo "@ phase-succeeded $out $curPhase"
fi
stopNest
done
}
# Execute the post-hooks.
runHook postHook
# Execute the global user hook (defined through the Nixpkgs
# configuration option stdenv.userHook). This can be used to set
# global compiler optimisation flags, for instance.
runHook userHook
dumpVars