@@ -39,6 +39,7 @@ serde_yaml = "0.9"
 toml = "0.9"
 cyclonedx-bom = "0.8"
 fs2 = "0.4"
+sha2 = "0.11"
 
 [dev-dependencies]
 tempfile = "3"
@@ -138,6 +138,7 @@ general_packages = ["ASPHERE", "KSPACE", "MOLECULE"]
 [[build.patches]]
 filename = "Orbit-2.0-portability.patch"
 sha256 = "4f43b42fdcf84d0cf634d993dd944f252c8243dc612a919fe2825d56f937c8eb"
+source = "patches/Orbit-2.0-portability.patch"
 
 [[dependencies.requirements]]
 name = "VTK"
@@ -147,7 +148,8 @@ roles = ["run"]
 Easyconfig parameters are typed data, not Python fragments. Requirements
 enter the canonical manifest and CycloneDX SBOM before Resolvo selects a
 version. Package planning requires every source and patch SHA-256; emitted
-checksums remain positional with sources first and patches second.
+checksums remain positional with sources first and patches second. Verified
+patch assets are copied beside every emitted recipe.
 
 ```sh
 eb-stack package plan \
 
@@ -140,11 +140,14 @@ patches:
 [[build.patches]]
 filename = "Orbit-2.0-portability.patch"
 sha256 = "4f43b42fdcf84d0cf634d993dd944f252c8243dc612a919fe2825d56f937c8eb"
+source = "patches/Orbit-2.0-portability.patch"
 #+end_src
 
 ~package inspect~ records a blocking ~patch:missing-sha256~ residual for an
 unchecked patch. ~package plan~ refuses to emit a buildable bundle until every
-source and patch checksum is present.
+source and patch checksum is present. Relative patch sources resolve against
+the package TOML file, and ~package plan~ copies verified patch bytes beside
+the emitted easyconfig.
 
 A QMCPACK profile set commonly contains a default MPI+OpenMP build and a
 separate ~-complex~ recipe:
 
@@ -20,14 +20,17 @@ moduleclass = "chem"
 [[build.patches]]
 filename = "LAMMPS-22Jul2025_install_lammps_python_package_in_eb_software_module.patch"
 sha256 = "0cab0fa4dc8b2c68b45cd9df4398b9c2c37d69dcd1dc054aacb44f78698a2c84"
+source = "patches/lammps/LAMMPS-22Jul2025_install_lammps_python_package_in_eb_software_module.patch"
 
 [[build.patches]]
 filename = "LAMMPS-2Aug2023_python_venv.patch"
 sha256 = "87fd13b0c66f0886877885412ff13dfd092782e2237ba1fae157f803437828d6"
+source = "patches/lammps/LAMMPS-2Aug2023_python_venv.patch"
 
 [[build.patches]]
 filename = "LAMMPS-22Jul2025_update4_DihedralStyle.patch"
 sha256 = "c265db38195f8830a36d5cde409d2ded1f8e9c47275eb29f0458e113d66f90f7"
+source = "patches/lammps/LAMMPS-22Jul2025_update4_DihedralStyle.patch"
 
 # Inputs implemented by the selected EasyBuild easyblock are typed data, not
 # Python snippets. Profile layers can override individual parameters.
 
@@ -0,0 +1,42 @@
+Add option in install.py to install lammps python packages in a configurable location
+diff --git a/python/install.py b/python/install.py
+index 352225e49d..ee9f2be068 100644
+--- a/python/install.py
++++ b/python/install.py
+@@ -29,6 +29,8 @@ parser.add_argument("-v", "--versionfile", required=True,
+                     help="path to the LAMMPS version.h source file")
+ parser.add_argument("-f", "--force", action="store_true", required=False, default=False,
+                     help="force installation of LAMMPS Python package")
++parser.add_argument("-i", "--installdir", required=True,
++                    help= "path to site-packages in lammps module")
+ 
+ args = parser.parse_args()
+ 
+@@ -72,6 +74,14 @@ if args.versionfile:
+   else:
+     args.versionfile = os.path.abspath(args.versionfile)
+ 
++if args.installdir:
++  if not os.path.exists(args.installdir):
++    print("\nERROR: LAMMPS site-packages file at %s does not exist\n" % args.installdir)
++    parser.print_help()
++    sys.exit(1)
++  else:
++    args.installdir = os.path.abspath(args.installdir)
++
+ olddir = os.path.abspath('.')
+ pythondir = os.path.abspath(os.path.join(args.package,'..'))
+ os.putenv('LAMMPS_VERSION_FILE',os.path.abspath(args.versionfile))
+@@ -146,6 +156,12 @@ else:
+   print("Installing wheel into system site-packages folder")
+   py_exe = sys.executable
+ 
++try:
++  txt = subprocess.check_output([py_exe, '-m', 'pip', 'install', '--force-reinstall', wheel, '--target', args.installdir], stderr=subprocess.STDOUT, shell=False)
++  print(txt)
++  sys.exit(0)
++except subprocess.CalledProcessError as err:
++  sys.exit(err.output.decode('UTF-8'))
+ try:
+   if args.force:
+     txt = subprocess.check_output([py_exe, '-m', 'pip', 'install', '--force-reinstall', '--break-system-packages', wheel], stderr=subprocess.STDOUT, shell=False)
@@ -0,0 +1,16 @@
+Patch to relax the original epsilon of 1.0e-13 to 1.3e-13 to get the test jobs working
+See: https://docs.lammps.org/Build_development.html#unit-tests-for-force-styles
+Author: J. Saßmannshausen (Imperial College London/UK)
+diff --git a/lammps-stable_22Jul2025_update4.orig/unittest/force-styles/tests/dihedral-table_spline.yaml b/lammps-stable_22Jul2025_update4/unittest/force-styles/tests/dihedral-table_spline.yaml
+index 10e56e4..43dabec 100644
+--- a/lammps-stable_22Jul2025_update4.orig/unittest/force-styles/tests/dihedral-table_spline.yaml
++++ b/lammps-stable_22Jul2025_update4/unittest/force-styles/tests/dihedral-table_spline.yaml
+@@ -1,7 +1,7 @@
+ ---
+ lammps_version: 22 Dec 2022
+ date_generated: Mon Dec 26 16:49:37 2022
+-epsilon: 1.0e-13
++epsilon: 1.3e-13
+ skip_tests:
+ prerequisites: ! |
+   atom full
@@ -0,0 +1,29 @@
+Patch Python installation to ensure system packages are used and not updated.
+diff --git a/python/install.py b/python/install.py
+index fd9f95f1bf..42f404224a 100644
+--- a/python/install.py
++++ b/python/install.py
+@@ -97,7 +97,7 @@ shutil.copy(args.lib,'lammps')
+ # create a virtual environment for building the wheel
+ shutil.rmtree('buildwheel', True)
+ try:
+-  txt = subprocess.check_output([sys.executable, '-m', 'venv', 'buildwheel'], stderr=subprocess.STDOUT, shell=False)
++  txt = subprocess.check_output([sys.executable, '-m', 'venv', '--system-site-packages', 'buildwheel'], stderr=subprocess.STDOUT, shell=False)
+   print(txt.decode('UTF-8'))
+ except subprocess.CalledProcessError as err:
+   sys.exit("Failed to create a virtual environment: {0}".format(err.output.decode('UTF-8')))
+diff --git a/python/makewheel.py b/python/makewheel.py
+index f13ad110ce..014756ddbd 100644
+--- a/python/makewheel.py
++++ b/python/makewheel.py
+@@ -23,8 +23,8 @@ sys.real_prefix = sys.prefix
+ sys.prefix = base
+ 
+ # update pip and install all requirements to build the wheel
+-os.system('python -m pip install --upgrade pip')
+-os.system('python -m pip install --upgrade -r wheel_requirements.txt')
++os.system('python -m pip install pip')
++os.system('python -m pip install -r wheel_requirements.txt')
+ 
+ print("Building new binary wheel")
+ os.system('python -m build -n --wheel -o .')
@@ -61,10 +61,13 @@ Declare patches as checked artifacts:
 [[build.patches]]
 filename = "Package-1.0-portability.patch"
 sha256 = "4f43b42fdcf84d0cf634d993dd944f252c8243dc612a919fe2825d56f937c8eb"
+source = "patches/Package-1.0-portability.patch"
 ```
 
 `package plan` rejects missing or malformed patch checksums. Checksum order in
 the emitted easyconfig is all source artifacts followed by all patch artifacts.
+Relative sources resolve against the package TOML, and verified patch bytes are
+copied beside the emitted easyconfig.
 
 Create one product profile per independently installable variant. Each profile emits one `.eb` file.
 
 
@@ -158,6 +158,8 @@ pub fn package_plan_from_foreign(recipe: &ForeignRecipe, toolchain: &Toolchain)
                 .map(|filename| PatchArtifact {
                     filename: filename.clone(),
                     sha256: None,
+                    source: None,
+                    resolved_source: None,
                 })
                 .collect(),
             easyconfig_parameters: BTreeMap::new(),