nixpkgs/pkgs/build-support/build-bazel-package/default.nix
Luke Granger-Brown d7d4a92695 buildBazelPackage: add "fetchConfigured" for fetching only things required for the build
"bazel fetch" will, by default, fetch everything that _might_ be used,
including things that will later be discarded due to the way the build
is configured.

Concretely, this means that for some builds of Java packages, this will
avoid failures where the builder tries to retrieve the JDK from /usr/share/java
(or equivalent).

This also means that for most packages we can fetch _fewer_ dependencies,
since the standard tree pruning for artifacts to fetch will take effect.

fetchConfigured is disabled by default since it changes the fetch hashes
of tensorflow/tensorflow2 (since it ends up fetching less).
2020-07-17 18:29:58 +02:00

217 lines
7.4 KiB
Nix

{ stdenv
, bazel
, cacert
, lib
}:
let
bazelPkg = bazel;
in
args@{
name
, bazel ? bazelPkg
, bazelFlags ? []
, bazelBuildFlags ? []
, bazelFetchFlags ? []
, bazelTarget
, buildAttrs
, fetchAttrs
# Newer versions of Bazel are moving away from built-in rules_cc and instead
# allow fetching it as an external dependency in a WORKSPACE file[1]. If
# removed in the fixed-output fetch phase, building will fail to download it.
# This can be seen e.g. in #73097
#
# This option allows configuring the removal of rules_cc in cases where a
# project depends on it via an external dependency.
#
# [1]: https://github.com/bazelbuild/rules_cc
, removeRulesCC ? true
, removeLocalConfigCc ? true
, removeLocal ? true
# Use build --nobuild instead of fetch. This allows fetching the dependencies
# required for the build as configured, rather than fetching all the dependencies
# which may not work in some situations (e.g. Java code which ends up relying on
# Debian-specific /usr/share/java paths, but doesn't in the configured build).
, fetchConfigured ? false
, ...
}:
let
fArgs = removeAttrs args [ "buildAttrs" "fetchAttrs" "removeRulesCC" ];
fBuildAttrs = fArgs // buildAttrs;
fFetchAttrs = fArgs // removeAttrs fetchAttrs [ "sha256" ];
in stdenv.mkDerivation (fBuildAttrs // {
inherit name bazelFlags bazelBuildFlags bazelFetchFlags bazelTarget;
deps = stdenv.mkDerivation (fFetchAttrs // {
name = "${name}-deps.tar.gz";
inherit bazelFlags bazelBuildFlags bazelFetchFlags bazelTarget;
impureEnvVars = lib.fetchers.proxyImpureEnvVars;
nativeBuildInputs = fFetchAttrs.nativeBuildInputs or [] ++ [ bazel ];
preHook = fFetchAttrs.preHook or "" + ''
export bazelOut="$(echo ''${NIX_BUILD_TOP}/output | sed -e 's,//,/,g')"
export bazelUserRoot="$(echo ''${NIX_BUILD_TOP}/tmp | sed -e 's,//,/,g')"
export HOME="$NIX_BUILD_TOP"
export USER="nix"
# This is needed for git_repository with https remotes
export GIT_SSL_CAINFO="${cacert}/etc/ssl/certs/ca-bundle.crt"
# This is needed for Bazel fetchers that are themselves programs (e.g.
# rules_go using the go toolchain)
export SSL_CERT_FILE="${cacert}/etc/ssl/certs/ca-bundle.crt"
'';
buildPhase = fFetchAttrs.buildPhase or ''
runHook preBuild
# Bazel computes the default value of output_user_root before parsing the
# flag. The computation of the default value involves getting the $USER
# from the environment. I don't have that variable when building with
# sandbox enabled. Code here
# https://github.com/bazelbuild/bazel/blob/9323c57607d37f9c949b60e293b573584906da46/src/main/cpp/startup_options.cc#L123-L124
#
# On macOS Bazel will use the system installed Xcode or CLT toolchain instead of the one in the PATH unless we pass BAZEL_USE_CPP_ONLY_TOOLCHAIN
# We disable multithreading for the fetching phase since it can lead to timeouts with many dependencies/threads:
# https://github.com/bazelbuild/bazel/issues/6502
BAZEL_USE_CPP_ONLY_TOOLCHAIN=1 \
USER=homeless-shelter \
bazel \
--output_base="$bazelOut" \
--output_user_root="$bazelUserRoot" \
${if fetchConfigured then "build --nobuild" else "fetch"} \
--loading_phase_threads=1 \
$bazelFlags \
$bazelFetchFlags \
$bazelTarget
runHook postBuild
'';
installPhase = fFetchAttrs.installPhase or ''
runHook preInstall
# Remove all built in external workspaces, Bazel will recreate them when building
rm -rf $bazelOut/external/{bazel_tools,\@bazel_tools.marker}
${if removeRulesCC then "rm -rf $bazelOut/external/{rules_cc,\\@rules_cc.marker}" else ""}
rm -rf $bazelOut/external/{embedded_jdk,\@embedded_jdk.marker}
${if removeLocalConfigCc then "rm -rf $bazelOut/external/{local_config_cc,\@local_config_cc.marker}" else ""}
${if removeLocal then "rm -rf $bazelOut/external/{local_*,\@local_*.marker}" else ""}
# Clear markers
find $bazelOut/external -name '@*\.marker' -exec sh -c 'echo > {}' \;
# Remove all vcs files
rm -rf $(find $bazelOut/external -type d -name .git)
rm -rf $(find $bazelOut/external -type d -name .svn)
rm -rf $(find $bazelOut/external -type d -name .hg)
# Removing top-level symlinks along with their markers.
# This is needed because they sometimes point to temporary paths (?).
# For example, in Tensorflow-gpu build:
# platforms -> NIX_BUILD_TOP/tmp/install/35282f5123611afa742331368e9ae529/_embedded_binaries/platforms
find $bazelOut/external -maxdepth 1 -type l | while read symlink; do
name="$(basename "$symlink")"
rm "$symlink"
test -f "$bazelOut/external/@$name.marker" && rm "$bazelOut/external/@$name.marker"
done
# Patching symlinks to remove build directory reference
find $bazelOut/external -type l | while read symlink; do
new_target="$(readlink "$symlink" | sed "s,$NIX_BUILD_TOP,NIX_BUILD_TOP,")"
rm "$symlink"
ln -sf "$new_target" "$symlink"
done
echo '${bazel.name}' > $bazelOut/external/.nix-bazel-version
(cd $bazelOut/ && tar czf $out --sort=name --mtime='@1' --owner=0 --group=0 --numeric-owner external/)
runHook postInstall
'';
dontFixup = true;
allowedRequisites = [];
outputHashAlgo = "sha256";
outputHash = fetchAttrs.sha256;
});
nativeBuildInputs = fBuildAttrs.nativeBuildInputs or [] ++ [ (bazel.override { enableNixHacks = true; }) ];
preHook = fBuildAttrs.preHook or "" + ''
export bazelOut="$NIX_BUILD_TOP/output"
export bazelUserRoot="$NIX_BUILD_TOP/tmp"
export HOME="$NIX_BUILD_TOP"
'';
preConfigure = ''
mkdir -p "$bazelOut"
(cd $bazelOut && tar xfz $deps)
test "${bazel.name}" = "$(<$bazelOut/external/.nix-bazel-version)" || {
echo "fixed output derivation was built for a different bazel version" >&2
echo " got: $(<$bazelOut/external/.nix-bazel-version)" >&2
echo "expected: ${bazel.name}" >&2
exit 1
}
chmod -R +w $bazelOut
find $bazelOut -type l | while read symlink; do
ln -sf $(readlink "$symlink" | sed "s,NIX_BUILD_TOP,$NIX_BUILD_TOP,") "$symlink"
done
'' + fBuildAttrs.preConfigure or "";
buildPhase = fBuildAttrs.buildPhase or ''
runHook preBuild
# Bazel sandboxes the execution of the tools it invokes, so even though we are
# calling the correct nix wrappers, the values of the environment variables
# the wrappers are expecting will not be set. So instead of relying on the
# wrappers picking them up, pass them in explicitly via `--copt`, `--linkopt`
# and related flags.
#
copts=()
host_copts=()
for flag in $NIX_CFLAGS_COMPILE; do
copts+=( "--copt=$flag" )
host_copts+=( "--host_copt=$flag" )
done
for flag in $NIX_CXXSTDLIB_COMPILE; do
copts+=( "--copt=$flag" )
host_copts+=( "--host_copt=$flag" )
done
linkopts=()
host_linkopts=()
for flag in $NIX_LDFLAGS; do
linkopts+=( "--linkopt=-Wl,$flag" )
host_linkopts+=( "--host_linkopt=-Wl,$flag" )
done
BAZEL_USE_CPP_ONLY_TOOLCHAIN=1 \
USER=homeless-shelter \
bazel \
--output_base="$bazelOut" \
--output_user_root="$bazelUserRoot" \
build \
-j $NIX_BUILD_CORES \
"''${copts[@]}" \
"''${host_copts[@]}" \
"''${linkopts[@]}" \
"''${host_linkopts[@]}" \
$bazelFlags \
$bazelBuildFlags \
$bazelTarget
runHook postBuild
'';
})