diff --git a/craft_application/services/project.py b/craft_application/services/project.py
index 4aca1f2f7..44027b0a8 100644
--- a/craft_application/services/project.py
+++ b/craft_application/services/project.py
@@ -759,6 +759,9 @@ def check_base_is_supported(self, verb: str = "pack") -> None:
     def is_effective_base_eol(self) -> bool:
         """Determine whether the base on which to build is end-of-life."""
         base = craft_platforms.DistroBase.from_str(self.get().effective_base)
+        if base.series == "devel":
+            # A devel series is never considered end-of-life.
+            return False
         return not self._is_supported_on(base=base, date=datetime.date.today())
 
     def base_eol_soon_date(self) -> datetime.date | None:
diff --git a/spread.yaml b/spread.yaml
index ea98ccd87..9a90d80f8 100644
--- a/spread.yaml
+++ b/spread.yaml
@@ -157,6 +157,8 @@ backends:
           workers: 4
       - ubuntu-25.10-64:
           workers: 4
+      - ubuntu-26.04-64:
+          workers: 4
     prepare: |
       # Ubuntu 20.04 requires a newer kernel, so we prepare it with an HWE kernel and
       # reboot. Note that we're only doing this here because for OpenStack we
diff --git a/tests/spread/witchcraft/pack-devel-build-base/task.yaml b/tests/spread/witchcraft/pack-devel-build-base/task.yaml
new file mode 100644
index 000000000..b996bb65d
--- /dev/null
+++ b/tests/spread/witchcraft/pack-devel-build-base/task.yaml
@@ -0,0 +1,19 @@
+summary: test packing witchcraft with build-base devel and --ignore=unmaintained
+
+# Regression test for https://github.com/canonical/craft-application/issues/1152
+#
+# ProjectService.is_effective_base_eol() did not handle a build-base of "devel"
+# (or any base unrecognized by distro-support), crashing with an unhandled
+# UnknownVersionError. This is only exercised when the --ignore=unmaintained
+# flag is used, since that's the only path calling is_effective_base_eol().
+
+execute: |
+  witchcraft pack --ignore=unmaintained --destructive-mode
+
+  if [[ $(find . -maxdepth 1 -name '*.witchcraft') == "" ]]; then
+    echo "No witchcraft file created" >> /dev/stderr
+    exit 1
+  fi
+
+restore: |
+  rm -f *.witchcraft
diff --git a/tests/spread/witchcraft/pack-devel-build-base/witchcraft.yaml b/tests/spread/witchcraft/pack-devel-build-base/witchcraft.yaml
new file mode 100644
index 000000000..6523a8a4a
--- /dev/null
+++ b/tests/spread/witchcraft/pack-devel-build-base/witchcraft.yaml
@@ -0,0 +1,21 @@
+name: eol-devel-test
+version: "0.1"
+summary: Test packing with a devel build-base and --ignore=unmaintained.
+description: |
+  Regression test for https://github.com/canonical/craft-application/issues/1152
+
+  This tests that witchcraft, which has check_supported_base enabled, can
+  pack a project with `base: bare` and `build-base: devel` when
+  `--ignore=unmaintained` is passed, without crashing with an
+  UnknownVersionError from distro-support.
+
+base: bare
+build-base: ubuntu@devel
+platforms:
+  platform-independent:
+    build-on: [amd64, arm64, ppc64el, s390x, riscv64]
+    build-for: [all]
+
+parts:
+  my-test:
+    plugin: nil
diff --git a/tests/unit/services/test_project.py b/tests/unit/services/test_project.py
index e82e16c98..5b7e6d664 100644
--- a/tests/unit/services/test_project.py
+++ b/tests/unit/services/test_project.py
@@ -32,6 +32,7 @@
 from craft_application.services.project import ProjectService
 from craft_application.services.service_factory import ServiceFactory
 from craft_parts import ProjectVar, ProjectVarInfo
+from distro_support.errors import UnknownDistributionError, UnknownVersionError
 from hypothesis import given, strategies
 
 
@@ -1002,6 +1003,57 @@ def test_check_base_eol_soon_date(
     assert real_project_service.base_eol_soon_date() == expected_date
 
 
+@freezegun.freeze_time("2027-01-01")
+@pytest.mark.parametrize(
+    ("base", "build_base", "expected"),
+    [
+        ("ubuntu@22.04", None, False),
+        pytest.param("ubuntu@16.04", None, True, id="eol-base"),
+        pytest.param("bare", "ubuntu@16.04", True, id="eol-build-base"),
+        pytest.param("ubuntu@22.04", "ubuntu@devel", False, id="devel-build-base"),
+        pytest.param("bare", "ubuntu@devel", False, id="devel-build-base-no-base"),
+    ],
+)
+@pytest.mark.usefixtures("fake_project_file")
+def test_is_effective_base_eol(
+    real_project_service: ProjectService,
+    base: str,
+    build_base: str | None,
+    expected: bool,
+):
+    real_project_service.configure(platform=None, build_for=None)
+    raw_project = real_project_service._load_raw_project()
+    if build_base:
+        raw_project["build-base"] = build_base
+    raw_project["base"] = base
+
+    assert real_project_service.is_effective_base_eol() is expected
+
+
+@freezegun.freeze_time("2027-01-01")
+@pytest.mark.parametrize(
+    ("base", "build_base"),
+    [
+        pytest.param("nonexistent@0.0", None, id="nonexistent-distribution"),
+        pytest.param("ubuntu@99.99", None, id="unknown-ubuntu-series"),
+    ],
+)
+@pytest.mark.usefixtures("fake_project_file")
+def test_is_effective_base_eol_unknown_base_raises(
+    real_project_service: ProjectService,
+    base: str,
+    build_base: str | None,
+):
+    real_project_service.configure(platform=None, build_for=None)
+    raw_project = real_project_service._load_raw_project()
+    if build_base:
+        raw_project["build-base"] = build_base
+    raw_project["base"] = base
+
+    with pytest.raises((UnknownDistributionError, UnknownVersionError)):
+        real_project_service.is_effective_base_eol()
+
+
 def test_deep_update(fake_project_file, real_project_service: ProjectService):
     """Test the deep update of a project model."""
     fake_project_file.write_text(