diff --git a/build/fsfe_website_build/build.py b/build/fsfe_website_build/build.py
index 475d94448e..559bfd208b 100755
--- a/build/fsfe_website_build/build.py
+++ b/build/fsfe_website_build/build.py
@@ -55,6 +55,12 @@ def parse_arguments() -> argparse.Namespace:
         type=int,
         default=multiprocessing.cpu_count(),
     )
+    parser.add_argument(
+        "--source",
+        help="Source directory, that contains the sites and global data",
+        default=Path(),
+        type=Path,
+    )
     parser.add_argument(
         "--serve",
         help="Serve the webpages after rebuild",
@@ -63,8 +69,8 @@ def parse_arguments() -> argparse.Namespace:
     parser.add_argument(
         "--sites",
         help="What site directories to build",
-        default=[path for path in Path().glob("?*.??*") if path.is_dir()],
-        type=lambda sites: [Path(site) for site in sites.split(",")],
+        default=None,
+        type=str,
     )
     parser.add_argument(
         "--stage",
@@ -80,9 +86,17 @@ def parse_arguments() -> argparse.Namespace:
         name@host:path?port.
         """),
         type=str,
-        default="./output/final",
+        default=None,
     )
-    return parser.parse_args()
+    args = parser.parse_args()
+    args.sites = (
+        [path for path in args.source.glob("?*.??*") if path.is_dir()]
+        if args.sites is None
+        else [args.source.joinpath(site) for site in args.sites.split(",")]
+    )
+    if args.target is None:
+        args.target = str(args.source.joinpath("output/final"))
+    return args
 
 
 def main() -> None:
@@ -102,7 +116,7 @@ def main() -> None:
 
         # TODO Should also be triggered whenever any build python file is changed
         if args.full:
-            full()
+            full(args.source)
         # -----------------------------------------------------------------------------
         # Create XML symlinks
         # -----------------------------------------------------------------------------
@@ -115,11 +129,12 @@ def main() -> None:
         # otherwise. This symlinks make sure that phase 2 can easily use the right file
         # for each language
         global_symlinks(
+            args.source,
             (
                 args.languages
                 if args.languages
                 else sorted(
-                    (path.name for path in Path().glob("global/languages/??")),
+                    (path.name for path in args.source.glob("global/languages/??")),
                 )
             ),
             pool,
@@ -128,7 +143,9 @@ def main() -> None:
         stage_required = any(
             [args.stage, "@" in args.target, ":" in args.target, "," in args.target],
         )
-        working_target = Path("./output/stage" if stage_required else args.target)
+        working_target = Path(
+            f"{args.source}/output/stage" if stage_required else args.target
+        )
         # the two middle phases are unconditional, and run on a per site basis
         for site in args.sites:
             logger.info("Processing %s", site)
@@ -141,6 +158,7 @@ def main() -> None:
             # Do not get access to languages to be built in,
             # and other benefits of being ran later.
             prepare_early_subdirectories(
+                args.source,
                 site,
                 args.processes,
             )
@@ -152,8 +170,14 @@ def main() -> None:
                 )
             )
             # Processes needed only for subdir stuff
-            phase1_run(site, languages, args.processes, pool)
-            phase2_run(site, languages, pool, working_target.joinpath(site))
+            phase1_run(args.source, site, languages, args.processes, pool)
+            phase2_run(
+                args.source,
+                site,
+                languages,
+                pool,
+                working_target.joinpath(site.name),
+            )
 
         logger.info("Starting Phase 3 - Global Conditional Finishing")
         if stage_required:
diff --git a/build/fsfe_website_build/lib/process_file.py b/build/fsfe_website_build/lib/process_file.py
index fea8999d53..b90969d0c3 100644
--- a/build/fsfe_website_build/lib/process_file.py
+++ b/build/fsfe_website_build/lib/process_file.py
@@ -47,7 +47,7 @@ def _get_attributes(file: Path) -> dict:
     return dict(attributes)
 
 
-def _get_trlist(file: Path) -> etree.Element:
+def _get_trlist(source: Path, file: Path) -> etree.Element:
     """
     list all languages a file exists in by globbing up
     the shortname (i.e. file path with file ending omitted)
@@ -58,12 +58,16 @@ def _get_trlist(file: Path) -> etree.Element:
     for path in file.parent.glob(f"{get_basename(file)}.??{file.suffix}"):
         tr = etree.SubElement(trlist, "tr", id=lang_from_filename(path))
         tr.text = (
-            Path(f"global/languages/{lang_from_filename(path)}").read_text().strip()
+            source.joinpath(f"global/languages/{lang_from_filename(path)}")
+            .read_text()
+            .strip()
         )
     return trlist
 
 
-def _get_set(action_file: Path, lang: str, parser: etree.XMLParser) -> etree.Element:
+def _get_set(
+    source: Path, action_file: Path, lang: str, parser: etree.XMLParser
+) -> etree.Element:
     """
     import elements from source files, add file name
     attribute to first element included from each file
@@ -75,7 +79,7 @@ def _get_set(action_file: Path, lang: str, parser: etree.XMLParser) -> etree.Ele
 
     if list_file.exists():
         with list_file.open("r") as file:
-            for path in (Path(line.strip()) for line in file):
+            for path in (source.joinpath(line.strip()) for line in file):
                 path_xml = (
                     path.with_suffix(f".{lang}.xml")
                     if path.with_suffix(f".{lang}.xml").exists()
@@ -87,6 +91,7 @@ def _get_set(action_file: Path, lang: str, parser: etree.XMLParser) -> etree.Ele
 
 
 def _get_document(
+    source: Path,
     action_lang: str,
     action_file: Path,
     lang: str,
@@ -97,12 +102,14 @@ def _get_document(
         language=action_lang,
         **_get_attributes(action_file),
     )
-    document.append(_get_set(action_file, lang, parser))
+    document.append(_get_set(source, action_file, lang, parser))
     document.extend(_get_xmls(action_file, parser))
     return document
 
 
-def _build_xmlstream(infile: Path, parser: etree.XMLParser) -> etree.Element:
+def _build_xmlstream(
+    source: Path, infile: Path, parser: etree.XMLParser
+) -> etree.Element:
     """
     assemble the xml stream for feeding into xsltproc
     the expected shortname and language flag indicate
@@ -128,8 +135,8 @@ def _build_xmlstream(infile: Path, parser: etree.XMLParser) -> etree.Element:
         .with_suffix("")
         .suffix.removeprefix(".")
     )
-    topbanner_xml = Path(f"global/data/topbanner/.topbanner.{lang}.xml")
-    texts_xml = Path(f"global/data/texts/.texts.{lang}.xml")
+    topbanner_xml = source.joinpath(f"global/data/topbanner/.topbanner.{lang}.xml")
+    texts_xml = source.joinpath(f"global/data/texts/.texts.{lang}.xml")
     date = str(datetime.now().date())
     action_lang = ""
     translation_state = ""
@@ -168,7 +175,7 @@ def _build_xmlstream(infile: Path, parser: etree.XMLParser) -> etree.Element:
     )
 
     # Add the subelements
-    page.append(_get_trlist(infile))
+    page.append(_get_trlist(source, infile))
 
     # Make the relevant subelmenets
     # and then add the relevant xmls to it
@@ -176,23 +183,27 @@ def _build_xmlstream(infile: Path, parser: etree.XMLParser) -> etree.Element:
     topbanner.extend(_get_xmls(topbanner_xml, parser))
 
     textsetbackup = etree.SubElement(page, "textsetbackup")
-    textsetbackup.extend(_get_xmls(Path("global/data/texts/texts.en.xml"), parser))
+    textsetbackup.extend(
+        _get_xmls(source.joinpath("global/data/texts/texts.en.xml"), parser)
+    )
 
     textset = etree.SubElement(page, "textset")
     textset.extend(_get_xmls(texts_xml, parser))
 
-    page.append(_get_document(action_lang, action_file, lang, parser))
+    page.append(_get_document(source, action_lang, action_file, lang, parser))
     return page
 
 
-def process_file(infile: Path, transform: etree.XSLT) -> etree._XSLTResultTree:
+def process_file(
+    source: Path, infile: Path, transform: etree.XSLT
+) -> etree._XSLTResultTree:
     """
     Process a given file using the correct xsl sheet
     """
     logger.debug("Processing %s", infile)
     lang = lang_from_filename(infile)
     parser = etree.XMLParser(remove_blank_text=True, remove_comments=True)
-    xmlstream = _build_xmlstream(infile, parser)
+    xmlstream = _build_xmlstream(source, infile, parser)
     result = transform(xmlstream)
     # And now a bunch of regexes to fix some links.
     # xx is the language code in all comments
diff --git a/build/fsfe_website_build/phase0/full.py b/build/fsfe_website_build/phase0/full.py
index 7d8fa01466..5e8437db54 100644
--- a/build/fsfe_website_build/phase0/full.py
+++ b/build/fsfe_website_build/phase0/full.py
@@ -3,18 +3,29 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 
 import logging
+from pathlib import Path
 
 from fsfe_website_build.lib.misc import run_command
 
 logger = logging.getLogger(__name__)
 
 
-def full() -> None:
+def full(source: Path) -> None:
     """
     Git clean the repo to remove all cached artifacts
     Excluded the root .venv repo, as removing it mid build breaks the build, obviously
     """
     logger.info("Performing a full rebuild, git cleaning")
     run_command(
-        ["git", "clean", "-fdx", "--exclude", "/.venv", "--exclude", "/.nltk_data"],
+        [
+            "git",
+            "--git-dir",
+            str(source) + "/.git",
+            "clean",
+            "-fdx",
+            "--exclude",
+            "/.venv",
+            "--exclude",
+            "/.nltk_data",
+        ],
     )
diff --git a/build/fsfe_website_build/phase0/global_symlinks.py b/build/fsfe_website_build/phase0/global_symlinks.py
index 2001fbb6f2..2aca39d461 100644
--- a/build/fsfe_website_build/phase0/global_symlinks.py
+++ b/build/fsfe_website_build/phase0/global_symlinks.py
@@ -10,21 +10,23 @@ from pathlib import Path
 logger = logging.getLogger(__name__)
 
 
-def _do_symlinking(link_type: str, lang: str) -> None:
+def _do_symlinking(source: Path, link_type: str, lang: str) -> None:
     """
     Helper function for global symlinking that is suitable for multithreading
     """
     target = (
-        Path(f"global/data/{link_type}/{link_type}.{lang}.xml")
-        if Path(f"global/data/{link_type}/{link_type}.{lang}.xml").exists()
-        else Path(f"global/data/{link_type}/{link_type}.en.xml")
+        source.joinpath(f"global/data/{link_type}/{link_type}.{lang}.xml")
+        if source.joinpath(f"global/data/{link_type}/{link_type}.{lang}.xml").exists()
+        else source.joinpath(f"global/data/{link_type}/{link_type}.en.xml")
     )
-    source = Path(f"global/data/{link_type}/.{link_type}.{lang}.xml")
-    if not source.exists():
-        source.symlink_to(target.relative_to(source.parent))
+    source_xml = source.joinpath(f"global/data/{link_type}/.{link_type}.{lang}.xml")
+    if not source_xml.exists():
+        source_xml.symlink_to(target.relative_to(source_xml.parent))
 
 
-def global_symlinks(languages: list[str], pool: multiprocessing.pool.Pool) -> None:
+def global_symlinks(
+    source: Path, languages: list[str], pool: multiprocessing.pool.Pool
+) -> None:
     """
     After this step, the following symlinks will exist:
     * global/data/texts/.texts.<lang>.xml for each language
@@ -36,4 +38,4 @@ def global_symlinks(languages: list[str], pool: multiprocessing.pool.Pool) -> No
     """
     logger.info("Creating global symlinks")
     link_types = ["texts", "topbanner"]
-    pool.starmap(_do_symlinking, product(link_types, languages))
+    pool.starmap(_do_symlinking, product([source], link_types, languages))
diff --git a/build/fsfe_website_build/phase0/prepare_early_subdirectories.py b/build/fsfe_website_build/phase0/prepare_early_subdirectories.py
index 81ce4115ae..146b7cd077 100644
--- a/build/fsfe_website_build/phase0/prepare_early_subdirectories.py
+++ b/build/fsfe_website_build/phase0/prepare_early_subdirectories.py
@@ -9,7 +9,9 @@ from pathlib import Path
 logger = logging.getLogger(__name__)
 
 
-def prepare_early_subdirectories(source_dir: Path, processes: int) -> None:
+def prepare_early_subdirectories(
+    source: Path, source_dir: Path, processes: int
+) -> None:
     """
     Find any early subdir scripts in subdirectories and run them
     """
@@ -21,7 +23,7 @@ def prepare_early_subdirectories(source_dir: Path, processes: int) -> None:
         # here for out subdir scripts
         import early_subdir  # noqa: PLC0415 # pyright: ignore [reportMissingImports]
 
-        early_subdir.run(processes, subdir_path)
+        early_subdir.run(source, processes, subdir_path)
         # Remove its path from where things can be imported
         sys.path.remove(str(subdir_path.resolve()))
         # Remove it from loaded modules
diff --git a/build/fsfe_website_build/phase1/prepare_subdirectories.py b/build/fsfe_website_build/phase1/prepare_subdirectories.py
index 882a774d35..b05bd4f750 100644
--- a/build/fsfe_website_build/phase1/prepare_subdirectories.py
+++ b/build/fsfe_website_build/phase1/prepare_subdirectories.py
@@ -10,6 +10,7 @@ logger = logging.getLogger(__name__)
 
 
 def prepare_subdirectories(
+    source: Path,
     source_dir: Path,
     languages: list[str],
     processes: int,
@@ -25,7 +26,7 @@ def prepare_subdirectories(
         # here for out subdir scripts
         import subdir  # noqa: PLC0415 # pyright: ignore [reportMissingImports]
 
-        subdir.run(languages, processes, subdir_path)
+        subdir.run(source, languages, processes, subdir_path)
         # Remove its path from where things can be imported
         sys.path.remove(str(subdir_path.resolve()))
         # Remove it from loaded modules
diff --git a/build/fsfe_website_build/phase1/run.py b/build/fsfe_website_build/phase1/run.py
index 4cf9ab40ef..ec81231b34 100644
--- a/build/fsfe_website_build/phase1/run.py
+++ b/build/fsfe_website_build/phase1/run.py
@@ -25,7 +25,8 @@ logger = logging.getLogger(__name__)
 
 
 def phase1_run(
-    source_dir: Path,
+    source: Path,
+    source_site: Path,
     languages: list[str],
     processes: int,
     pool: multiprocessing.pool.Pool,
@@ -41,9 +42,7 @@ def phase1_run(
 
     # This step recompiles the less files into the final CSS files to be
     # distributed to the web server.
-    update_css(
-        source_dir,
-    )
+    update_css(source_site)
     # -----------------------------------------------------------------------------
     # Update XSL stylesheets
     # -----------------------------------------------------------------------------
@@ -57,12 +56,12 @@ def phase1_run(
     # and events directories, the XSL files, if updated, will be copied for the
     # per-year archives.
 
-    update_stylesheets(source_dir, pool)
+    update_stylesheets(source_site, pool)
     # -----------------------------------------------------------------------------
     # Dive into subdirectories
     # -----------------------------------------------------------------------------
     # Find any makefiles in subdirectories and run them
-    prepare_subdirectories(source_dir, languages, processes)
+    prepare_subdirectories(source, source_site, languages, processes)
 
     # -----------------------------------------------------------------------------
     # Create XSL symlinks
@@ -74,14 +73,14 @@ def phase1_run(
     # determine which XSL script should be used to build a HTML page from a source
     # file.
 
-    update_defaultxsls(source_dir, pool)
+    update_defaultxsls(source_site, pool)
     # -----------------------------------------------------------------------------
     # Update local menus
     # -----------------------------------------------------------------------------
 
     # After this step, all .localmenu.??.xml files will be up to date.
 
-    update_localmenus(source_dir, languages, pool)
+    update_localmenus(source, source_site, languages, pool)
     # -----------------------------------------------------------------------------
     # Update XML filelists
     # -----------------------------------------------------------------------------
@@ -93,4 +92,4 @@ def phase1_run(
     #   correct XML files when generating the HTML pages. It is taken care that
     #   these files are only updated whenever their content actually changes, so
     #   they can serve as a prerequisite in the phase 2 Makefile.
-    update_xmllists(source_dir, languages, pool)
+    update_xmllists(source, source_site, languages, pool)
diff --git a/build/fsfe_website_build/phase1/update_localmenus.py b/build/fsfe_website_build/phase1/update_localmenus.py
index 1b0e7a71fe..21a55d533c 100755
--- a/build/fsfe_website_build/phase1/update_localmenus.py
+++ b/build/fsfe_website_build/phase1/update_localmenus.py
@@ -76,6 +76,7 @@ def _write_localmenus(
 
 
 def update_localmenus(
+    source: Path,
     source_dir: Path,
     languages: list[str],
     pool: multiprocessing.pool.Pool,
@@ -94,7 +95,9 @@ def update_localmenus(
         if xslt_root.xpath("//localmenu"):
             directory = xslt_root.xpath("//localmenu/@dir")
             directory = (
-                directory[0] if directory else str(file.parent.relative_to(Path()))
+                str(source.joinpath(directory[0]))
+                if directory
+                else str(file.parent.resolve())
             )
             if directory not in files_by_dir:
                 files_by_dir[directory] = set()
diff --git a/build/fsfe_website_build/phase1/update_stylesheets.py b/build/fsfe_website_build/phase1/update_stylesheets.py
index 2abdf5b19b..d3b4286f54 100755
--- a/build/fsfe_website_build/phase1/update_stylesheets.py
+++ b/build/fsfe_website_build/phase1/update_stylesheets.py
@@ -20,7 +20,7 @@ def _update_sheet(file: Path) -> None:
     """
     xslt_root = etree.parse(file)
     imports = [
-        file.parent.joinpath(imp.get("href")).resolve().relative_to(Path.cwd())
+        file.parent.joinpath(imp.get("href")).resolve()
         for imp in xslt_root.xpath(
             "//xsl:import", namespaces={"xsl": "http://www.w3.org/1999/XSL/Transform"}
         )
diff --git a/build/fsfe_website_build/phase1/update_xmllists.py b/build/fsfe_website_build/phase1/update_xmllists.py
index 6332b169c5..4fbaa4404b 100755
--- a/build/fsfe_website_build/phase1/update_xmllists.py
+++ b/build/fsfe_website_build/phase1/update_xmllists.py
@@ -21,7 +21,8 @@ from fsfe_website_build.lib.misc import (
 logger = logging.getLogger(__name__)
 
 
-def _update_for_base(
+def _update_for_base(  # noqa: PLR0913
+    source: Path,
     base: Path,
     all_xml: set[Path],
     nextyear: str,
@@ -56,14 +57,14 @@ def _update_for_base(
                 for xml_file in filter(
                     lambda xml_file:
                     # Matches glob pattern
-                    fnmatch.fnmatchcase(str(xml_file), pattern)
+                    fnmatch.fnmatchcase(str(xml_file.relative_to(source)), pattern)
                     # contains tag if tag in pattern
                     and (
                         any(
                             (
-                                etree.parse(
-                                    xml_file_with_ending,
-                                ).find(f".//tag[@key='{tag}']")
+                                etree.parse(xml_file_with_ending).find(
+                                    f".//tag[@key='{tag}']"
+                                )
                                 is not None
                                 for xml_file_with_ending in xml_file.parent.glob(
                                     f"{xml_file.name}.*.xml"
@@ -77,12 +78,14 @@ def _update_for_base(
                     and len(str(xml_file)) > 0,
                     all_xml,
                 ):
-                    matching_files.add(str(xml_file))
+                    matching_files.add(str(xml_file.relative_to(source)))
 
-    for file in Path().glob(f"{base}.??.xhtml"):
+    for file in base.parent.glob(f"{base.name}.??.xhtml"):
         xslt_root = etree.parse(file)
         for module in xslt_root.xpath("//module"):
-            matching_files.add(f"global/data/modules/{module.get('id')}".strip())
+            matching_files.add(
+                f"{source}/global/data/modules/{module.get('id').strip()}"
+            )
     matching_files = sorted(matching_files)
     update_if_changed(
         Path(f"{base.parent}/.{base.name}.xmllist"),
@@ -91,6 +94,7 @@ def _update_for_base(
 
 
 def _update_module_xmllists(
+    source: Path,
     source_dir: Path,
     languages: list[str],
     pool: multiprocessing.pool.Pool,
@@ -105,7 +109,7 @@ def _update_module_xmllists(
         for path in filter(
             lambda path: lang_from_filename(path) in languages,
             list(source_dir.glob("**/*.*.xml"))
-            + list(Path("global/").glob("**/*.*.xml")),
+            + list(source.joinpath("global/").glob("**/*.*.xml")),
         )
     }
     source_bases = {path.with_suffix("") for path in source_dir.glob("**/*.sources")}
@@ -123,23 +127,25 @@ def _update_module_xmllists(
     lastyear = str(datetime.datetime.today().year - 1)
     pool.starmap(
         _update_for_base,
-        ((base, all_xml, nextyear, thisyear, lastyear) for base in all_bases),
+        ((source, base, all_xml, nextyear, thisyear, lastyear) for base in all_bases),
     )
 
 
-def _check_xmllist_deps(file: Path) -> None:
+def _check_xmllist_deps(source: Path, file: Path) -> None:
     """
     If any of the sources in an xmllist are newer than it, touch the xmllist
     """
     xmls = set()
     with file.open(mode="r") as fileobj:
         for line in fileobj:
-            for newfile in Path().glob(line.strip() + ".??.xml"):
+            path_line = source.joinpath(line.strip())
+            for newfile in path_line.parent.glob(path_line.name + ".??.xml"):
                 xmls.add(newfile)
     touch_if_newer_dep(file, list(xmls))
 
 
 def _touch_xmllists_with_updated_deps(
+    source: Path,
     source_dir: Path,
     pool: multiprocessing.pool.Pool,
 ) -> None:
@@ -147,10 +153,14 @@ def _touch_xmllists_with_updated_deps(
     Touch all .xmllist files where one of the contained files has changed
     """
     logger.info("Checking contents of XML lists")
-    pool.map(_check_xmllist_deps, source_dir.glob("**/.*.xmllist"))
+    pool.starmap(
+        _check_xmllist_deps,
+        [(source, path) for path in source_dir.glob("**/.*.xmllist")],
+    )
 
 
 def update_xmllists(
+    source: Path,
     source_dir: Path,
     languages: list[str],
     pool: multiprocessing.pool.Pool,
@@ -172,5 +182,5 @@ def update_xmllists(
     When a tag has been removed from the last XML file where it has been used,
     the tagged-* are correctly deleted.
     """
-    _update_module_xmllists(source_dir, languages, pool)
-    _touch_xmllists_with_updated_deps(source_dir, pool)
+    _update_module_xmllists(source, source_dir, languages, pool)
+    _touch_xmllists_with_updated_deps(source, source_dir, pool)
diff --git a/build/fsfe_website_build/phase2/process_files.py b/build/fsfe_website_build/phase2/process_files.py
index 290560fb1b..f22e65e4c2 100644
--- a/build/fsfe_website_build/phase2/process_files.py
+++ b/build/fsfe_website_build/phase2/process_files.py
@@ -15,7 +15,8 @@ from fsfe_website_build.lib.process_file import process_file
 logger = logging.getLogger(__name__)
 
 
-def _process_set(
+def _process_set(  # noqa: PLR0913
+    source: Path,
     source_dir: Path,
     languages: list[str],
     target: Path,
@@ -63,12 +64,13 @@ def _process_set(
             ),
         ):
             logger.debug("Building %s", target_file)
-            result = process_file(source_file, transform)
+            result = process_file(source, source_file, transform)
             target_file.parent.mkdir(parents=True, exist_ok=True)
             result.write_output(target_file)
 
 
 def process_files(
+    source: Path,
     source_dir: Path,
     languages: list[str],
     pool: multiprocessing.pool.Pool,
@@ -103,13 +105,11 @@ def process_files(
             file.with_suffix("")
             .with_suffix(".xsl")
             .resolve()
-            .relative_to(source_dir.parent.resolve())
+            .relative_to(source.resolve())
         )
         # if that does not exist, default to
         xhtml_default_processor = (
-            file.parent.joinpath(".default.xsl")
-            .resolve()
-            .relative_to(source_dir.parent.resolve())
+            file.parent.joinpath(".default.xsl").resolve().relative_to(source.resolve())
         )
         xhtml_processor = (
             xhtml_named_processor
@@ -125,7 +125,7 @@ def process_files(
     pool.starmap(
         _process_set,
         (
-            (source_dir, languages, target, processor, files)
+            (source, source_dir, languages, target, processor, files)
             for processor, files in process_files_dict.items()
         ),
     )
diff --git a/build/fsfe_website_build/phase2/run.py b/build/fsfe_website_build/phase2/run.py
index fcd6dca26b..2031e7920b 100644
--- a/build/fsfe_website_build/phase2/run.py
+++ b/build/fsfe_website_build/phase2/run.py
@@ -18,6 +18,7 @@ logger = logging.getLogger(__name__)
 
 
 def phase2_run(
+    source: Path,
     source_dir: Path,
     languages: list[str],
     pool: multiprocessing.pool.Pool,
@@ -27,7 +28,7 @@ def phase2_run(
     Run all the necessary sub functions for phase2.
     """
     logger.info("Starting Phase 2 - Generating output")
-    process_files(source_dir, languages, pool, target)
+    process_files(source, source_dir, languages, pool, target)
     create_index_symlinks(pool, target)
     create_language_symlinks(pool, target)
     copy_files(source_dir, pool, target)
diff --git a/build/fsfe_website_build_tests/lib/process_file_test.py b/build/fsfe_website_build_tests/lib/process_file_test.py
index 9bb036ab49..bd82cca848 100644
--- a/build/fsfe_website_build_tests/lib/process_file_test.py
+++ b/build/fsfe_website_build_tests/lib/process_file_test.py
@@ -65,7 +65,7 @@ def process_file_link_rewrites_test(
     )
     assert isinstance(sample_xsl_transformer, etree.XSLT)
 
-    result_doc = process_file(xml_path, sample_xsl_transformer)
+    result_doc = process_file(Path(), xml_path, sample_xsl_transformer)
     assert isinstance(result_doc, etree._XSLTResultTree)
     # We get a list, but as we have only one link in the above sample
     # we only need to care about the first one
diff --git a/fsfe.org/events/subdir.py b/fsfe.org/events/subdir.py
index 41f3ee1176..844246b4e1 100644
--- a/fsfe.org/events/subdir.py
+++ b/fsfe.org/events/subdir.py
@@ -28,20 +28,20 @@ def _gen_archive_index(
             update_if_changed(directory.joinpath(f"index.{lang}.xhtml"), content)
 
 
-def _gen_index_sources(directory: Path) -> None:
+def _gen_index_sources(source: Path, directory: Path) -> None:
     update_if_changed(
         directory.joinpath("index.sources"),
         dedent(
             f"""\
-                {directory}/event-*:[]
-                {directory}/.event-*:[]
-                {directory.parent}/.localmenu:[]
+                {directory.relative_to(source)}/event-*:[]
+                {directory.relative_to(source)}/.event-*:[]
+                {directory.parent.relative_to(source)}/.localmenu:[]
             """,
         ),
     )
 
 
-def run(languages: list[str], processes: int, working_dir: Path) -> None:
+def run(source: Path, languages: list[str], processes: int, working_dir: Path) -> None:
     """
     preparation for news subdirectory
     """
@@ -54,5 +54,5 @@ def run(languages: list[str], processes: int, working_dir: Path) -> None:
         )
         logger.debug("Finished Archiving")
         # Generate index.sources for every year
-        pool.map(_gen_index_sources, years)
+        pool.starmap(_gen_index_sources, [(source, year) for year in years])
         logger.debug("Finished generating sources")
diff --git a/fsfe.org/internal/subdir.py b/fsfe.org/internal/subdir.py
index 17aa454849..dbdf76517e 100644
--- a/fsfe.org/internal/subdir.py
+++ b/fsfe.org/internal/subdir.py
@@ -15,7 +15,7 @@ from lxml import etree
 logger = logging.getLogger(__name__)
 
 
-def run(languages: list[str], processes: int, working_dir: Path) -> None:  # noqa: ARG001 # We allow unused args for subdirs
+def run(source: Path, languages: list[str], processes: int, working_dir: Path) -> None:  # noqa: ARG001 # We allow unused args for subdirs
     """
     Internal subdir preparation
     """
diff --git a/fsfe.org/news/subdir.py b/fsfe.org/news/subdir.py
index 3c93f8e040..508af20789 100644
--- a/fsfe.org/news/subdir.py
+++ b/fsfe.org/news/subdir.py
@@ -29,14 +29,14 @@ def _gen_archive_index(
             update_if_changed(directory.joinpath(f"index.{lang}.xhtml"), content)
 
 
-def _gen_index_sources(directory: Path) -> None:
+def _gen_index_sources(source: Path, directory: Path) -> None:
     update_if_changed(
         directory.joinpath("index.sources"),
         dedent(
             f"""\
-                {directory}/news-*:[]
-                {directory}/.news-*:[]
-                {directory.parent}/.localmenu:[]
+               {directory.relative_to(source)}/news-*:[]
+               {directory.relative_to(source)}/.news-*:[]
+               {directory.parent.relative_to(source)}/.localmenu:[]
             """,
         ),
     )
@@ -64,7 +64,7 @@ def _gen_xml_files(working_dir: Path, file: Path) -> None:
     )
 
 
-def run(languages: list[str], processes: int, working_dir: Path) -> None:
+def run(source: Path, languages: list[str], processes: int, working_dir: Path) -> None:
     """
     preparation for news subdirectory
     """
@@ -77,7 +77,7 @@ def run(languages: list[str], processes: int, working_dir: Path) -> None:
         )
         logger.debug("Finished Archiving")
         # Generate index.sources for every year
-        pool.map(_gen_index_sources, years)
+        pool.starmap(_gen_index_sources, [(source, year) for year in years])
         logger.debug("Finished generating sources")
         pool.starmap(
             _gen_xml_files,
diff --git a/fsfe.org/search/subdir.py b/fsfe.org/search/subdir.py
index 02976bc3b5..825a1f5e67 100644
--- a/fsfe.org/search/subdir.py
+++ b/fsfe.org/search/subdir.py
@@ -67,7 +67,7 @@ def _process_file(file: Path, stopwords: set[str]) -> dict:
     }
 
 
-def run(languages: list[str], processes: int, working_dir: Path) -> None:
+def run(source: Path, languages: list[str], processes: int, working_dir: Path) -> None:  # noqa: ARG001
     """
     This step runs a Python tool that creates an index of all news and
     articles. It extracts titles, teaser, tags, dates and potentially more.
diff --git a/fsfe.org/tags/subdir.py b/fsfe.org/tags/subdir.py
index 9882a0d3d0..5dd2685908 100755
--- a/fsfe.org/tags/subdir.py
+++ b/fsfe.org/tags/subdir.py
@@ -72,7 +72,7 @@ def _update_tag_sets(
     )
 
 
-def run(languages: list[str], processes: int, working_dir: Path) -> None:
+def run(source: Path, languages: list[str], processes: int, working_dir: Path) -> None:  # noqa: ARG001
     """
     Update Tag pages, xmllists and xmls
 
diff --git a/status.fsfe.org/filler/early_subdir.py b/status.fsfe.org/filler/early_subdir.py
index 9c96abca39..9538c3bf03 100644
--- a/status.fsfe.org/filler/early_subdir.py
+++ b/status.fsfe.org/filler/early_subdir.py
@@ -14,7 +14,7 @@ from lxml import etree
 logger = logging.getLogger(__name__)
 
 
-def run(processes: int, working_dir: Path) -> None:
+def run(source: Path, processes: int, working_dir: Path) -> None:
     """
     Place filler indices to encourage the site to
     ensure that status pages for all langs are build.
@@ -44,6 +44,6 @@ def run(processes: int, working_dir: Path) -> None:
                     ),
                     index_content,
                 )
-                for path in Path().glob("global/languages/*")
+                for path in source.glob("global/languages/*")
             ),
         )
diff --git a/status.fsfe.org/translations/subdir.py b/status.fsfe.org/translations/subdir.py
index 3a16c69ed8..6680fcc4b0 100644
--- a/status.fsfe.org/translations/subdir.py
+++ b/status.fsfe.org/translations/subdir.py
@@ -154,7 +154,7 @@ def _create_translation_file(
     update_if_changed(work_file, result_str)
 
 
-def run(languages: list[str], processes: int, working_dir: Path) -> None:
+def run(source: Path, languages: list[str], processes: int, working_dir: Path) -> None:  # noqa: ARG001
     """
     Build translation-status xmls for languages where the status has changed.
     Xmls are placed in target_dir, and only languages are processed.