Building macOS libraries can be non-deterministic

Building the native libraries on macOS is not always deterministic. Some of the shared libraries can be different from one build to the next on the same system with the same project path, such as 'libgstreamer-lite.dylib', 'libjavafx_font.dylib', and 'libjavafx_iio.dylib'.

SYSTEM / OS / JAVA RUNTIME INFORMATION

The following build tools were used:

- cmake version 3.26.3
- Command Line Tools for Xcode 14.2 version 14.2.0.0.1.1668646533
- OpenJDK Runtime Environment (build 19.0.2+7-44)
- Apache Ant(TM) version 1.10.13 compiled on January 4 2023

STEPS TO REPRODUCE

Set the environment variables by sourcing the file called 'jfxbuild.env'. Then run the Bash script called 'actions.sh' to build two copies of a simulated JavaFX GitHub Actions build and run the unit tests.

Both files are included in the SOURCE section below.

EXPECTED RESULTS

When the build script completes, the following command should show no output:

$ diff -qr build3 build4

ACTUAL RESULT

Instead, the command shows differences in some of the shared libraries and in the archives that include them:

$ diff -qr build3 build4
Files build3/artifacts/bundles/javafx-jmods-21.zip and build4/artifacts/bundles/javafx-jmods-21.zip differ
Files build3/artifacts/bundles/javafx-sdk-21.zip and build4/artifacts/bundles/javafx-sdk-21.zip differ
Files build3/artifacts/javafx-jmods-21/javafx.graphics.jmod and build4/artifacts/javafx-jmods-21/javafx.graphics.jmod differ
Files build3/artifacts/javafx-sdk-21/lib/libjavafx_font.dylib and build4/artifacts/javafx-sdk-21/lib/libjavafx_font.dylib differ
Files build3/artifacts/javafx-sdk-21/lib/libjavafx_iio.dylib and build4/artifacts/javafx-sdk-21/lib/libjavafx_iio.dylib differ
Files build3/javafx-exports.zip and build4/javafx-exports.zip differ
Files build3/jmods/javafx.graphics.jmod and build4/jmods/javafx.graphics.jmod differ
Files build3/modular-sdk/modules_libs/javafx.graphics/libjavafx_font.dylib and build4/modular-sdk/modules_libs/javafx.graphics/libjavafx_font.dylib differ
Files build3/modular-sdk/modules_libs/javafx.graphics/libjavafx_iio.dylib and build4/modular-sdk/modules_libs/javafx.graphics/libjavafx_iio.dylib differ
Files build3/publications/javafx.graphics-mac.jar and build4/publications/javafx.graphics-mac.jar differ
Files build3/sdk/lib/libjavafx_font.dylib and build4/sdk/lib/libjavafx_font.dylib differ
Files build3/sdk/lib/libjavafx_iio.dylib and build4/sdk/lib/libjavafx_iio.dylib differ

SOURCE CODE FOR AN EXECUTABLE TEST CASE

The file 'jfxbuild.env' that sets the environment variables:

-----------
#!/bin/bash
# Sets up the environment for building JavaFX
syspath=/usr/sbin:/usr/bin:/sbin:/bin

export CMAKE_HOME=$HOME/opt/cmake-3.26.3-macos-universal/CMake.app/Contents
export JAVA_HOME=$HOME/opt/jdk-19.0.2.jdk/Contents/Home
export ANT_HOME=$HOME/opt/apache-ant-1.10.13

SOURCE_DATE_EPOCH=$(git log -1 --pretty=%ct)
export SOURCE_DATE_EPOCH

# JDK_HOME and PATH are required by the build
export JDK_HOME=$JAVA_HOME
export PATH=$ANT_HOME/bin:$JAVA_HOME/bin:$CMAKE_HOME/bin:$syspath
-----------

The file 'actions.sh' that runs the two builds and the unit tests:

-----------
#!/bin/bash
# Creates two GitHub Actions builds and runs unit tests
trap exit INT TERM
set -o errexit

dir1=build3
dir2=build4

if [ -d $dir1 ] || [ -d $dir2 ]; then
    printf "Target directories exist: %s %s\n" $dir1 $dir2 >&2
    exit 1
fi

gradle () (
    set -o xtrace
    bash gradlew --no-daemon "$@"
)

printf "SOURCE_DATE_EPOCH=%s\n" "$SOURCE_DATE_EPOCH"
for dir in $dir1 $dir2; do
    gradle cleanAll
    gradle all
    mv build "$dir"
done
gradle all test -x :web:test
-----------

WORKAROUND

None.