diff --git a/.github/workflows/sanitizers.yml b/.github/workflows/sanitizers.yml
index 8042b446f8..5af5795390 100644
--- a/.github/workflows/sanitizers.yml
+++ b/.github/workflows/sanitizers.yml
@@ -36,6 +36,10 @@ jobs:
             label: ASan + UBSan
             image: ghcr.io/aethersdr/aethersdr-ci:latest
             build_type: Debug
+            # A Debug ASan tree with the core linked statically into ~250
+            # test executables outgrew the runner's disk ("No space left on
+            # device", three weeks running). One shared core keeps it near 17 GB.
+            shared_core: "ON"
             # ON here too, not only under TSan: the churn test's documented
             # failure class is a heap use-after-free on the receiver vector,
             # and a sequential UAF produces no TSan report — catching it is
@@ -63,6 +67,7 @@ jobs:
             # TSan cannot coexist with ASan, so build RelWithDebInfo and
             # inject the TSan flags ourselves.
             build_type: RelWithDebInfo
+            shared_core: "OFF"
             receiver_churn: "ON"
             extra_cxx: "-fsanitize=thread -g3 -fno-omit-frame-pointer -O1"
             extra_ld:  "-fsanitize=thread"
@@ -102,6 +107,7 @@ jobs:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1
 
       - name: Configure
+        id: configure
         env:
           # CFLAGS as well as CXXFLAGS. The tree is not all C++: WDSP and its
           # Win32 port, liquid-dsp, rnnoise and the other vendored C libraries
@@ -122,10 +128,12 @@ jobs:
           # that it is out of the default graph.
           cmake -B build -G Ninja \
             -DCMAKE_BUILD_TYPE=${{ matrix.sanitizer.build_type }} \
+            -DAETHER_SHARED_CORE=${{ matrix.sanitizer.shared_core }} \
             -DAETHER_ENABLE_HL2_RECEIVER_CHURN_TEST=${{ matrix.sanitizer.receiver_churn }} \
             -DAETHER_ENABLE_HL2_TX_LOOPBACK_TEST=ON
 
       - name: Build
+        id: build
         # The SAME sanitizer flags as Configure, because this step also runs
         # configure: vendored Opus is an ExternalProject_Add, so its child
         # CMake project configures during the parent's BUILD, when a Configure-
@@ -140,7 +148,34 @@ jobs:
           CFLAGS:   ${{ matrix.sanitizer.extra_cxx }}
           CXXFLAGS: ${{ matrix.sanitizer.extra_cxx }}
           LDFLAGS:  ${{ matrix.sanitizer.extra_ld }}
-        run: cmake --build build --parallel
+        run: |
+          # The after-build reading must survive a failed build, which is
+          # when it matters. Explicit status rather than an EXIT trap: this
+          # step runs under the container's sh, not bash.
+          df -h /
+          rc=0
+          cmake --build build --parallel || rc=$?
+          df -h /
+          exit "$rc"
+
+      # A Configure or Build failure skips every step below, ctest's report
+      # chain included, so the lane used to go dark with no artifact and no
+      # tracking issue (three weeks of "No space left on device"). This step
+      # leaves that chain a report, and a stable per-step fingerprint so the
+      # sticky issue collects repeats rather than opening one per week.
+      - name: Report a lane that did not build
+        id: nobuild
+        if: failure() && (steps.configure.outcome == 'failure' || steps.build.outcome == 'failure')
+        env:
+          FAILED_STEP: ${{ steps.configure.outcome == 'failure' && 'Configure' || 'Build' }}
+        run: |
+          {
+            echo "The lane did NOT run its tests: the $FAILED_STEP step failed."
+            echo "No result in this run is meaningful; the step log in the run says why."
+          } > report.txt
+          cp report.txt sanitizer.log
+          fp=$(printf 'nobuild:%s' "$FAILED_STEP" | sha256sum | cut -c1-12)
+          echo "fingerprint=${fp}" >> "$GITHUB_OUTPUT"
 
       - name: Run tests under sanitizer
         id: ctest
@@ -290,7 +325,7 @@ jobs:
           echo "fingerprint=${fp}" >> "$GITHUB_OUTPUT"
 
       - name: Upload sanitizer artifacts
-        if: steps.ctest.outputs.exit != '0'
+        if: (success() && steps.ctest.outputs.exit != '0') || (failure() && steps.nobuild.outcome == 'success')
         uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a
         with:
           name: ${{ matrix.sanitizer.id }}-${{ github.run_id }}
@@ -300,12 +335,12 @@ jobs:
           retention-days: 30
 
       - name: Open or update tracking issue
-        if: steps.ctest.outputs.exit != '0'
+        if: (success() && steps.ctest.outputs.exit != '0') || (failure() && steps.nobuild.outcome == 'success')
         uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3
         env:
           SAN_ID:     ${{ matrix.sanitizer.id }}
           SAN_LABEL:  ${{ matrix.sanitizer.label }}
-          FP:         ${{ steps.extract.outputs.fingerprint }}
+          FP:         ${{ steps.extract.outputs.fingerprint || steps.nobuild.outputs.fingerprint }}
           RUN_URL:    ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}
         with:
           script: |
diff --git a/.github/workflows/static-checks.yml b/.github/workflows/static-checks.yml
index bf83c5c5ae..ef85ffb881 100644
--- a/.github/workflows/static-checks.yml
+++ b/.github/workflows/static-checks.yml
@@ -141,6 +141,25 @@ jobs:
             fail=1
           fi
 
+          # 5. AETHER_SHARED_CORE=ON (the ASan lane's link mode) must produce a
+          #    shared core, and the default must stay static. The sanitizer
+          #    lane is weekly, so this is the only per-PR check of the option.
+          #    Asserted on the generated ninja file, like case 2.
+          if cmake -B /tmp/cfg-shared -S . -G Ninja \
+                   -DAETHER_SHARED_CORE=ON > /tmp/shared.log 2>&1; then
+            grep -q '^build libaethercore\.so' /tmp/cfg-shared/build.ninja \
+              || { echo "::error::AETHER_SHARED_CORE=ON configured, but no libaethercore.so rule"; fail=1; }
+          else
+            echo "::error::-DAETHER_SHARED_CORE=ON failed to configure"
+            tail -30 /tmp/shared.log
+            fail=1
+          fi
+          if [ -f /tmp/cfg-thread/build.ninja ] \
+             && ! grep -q '^build libaethercore\.a' /tmp/cfg-thread/build.ninja; then
+            echo "::error::the default configure no longer builds a static libaethercore.a"
+            fail=1
+          fi
+
           exit "$fail"
 
   static-checks:
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 871e3defc6..1b212df90c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -143,6 +143,27 @@ if(NOT AETHERSDR_SANITIZER STREQUAL "none")
     message(STATUS "AetherSDR: sanitizer = ${AETHERSDR_SANITIZER} (whole tree)")
     unset(_aether_san_list)
 endif()
+# Build libaethercore as one shared library instead of a static archive. The
+# ~250 test executables that link the core each absorb a full static copy
+# (~200 MB in a Debug ASan build), which exhausts a hosted runner's disk;
+# shared, they average ~13 MB. For the sanitizer lane only, never for releases:
+# the shipped app links the core statically.
+option(AETHER_SHARED_CORE "Build libaethercore as a shared library (sanitizer CI only)" OFF)
+if(AETHER_SHARED_CORE)
+    if(WIN32)
+        message(FATAL_ERROR "AETHER_SHARED_CORE is not supported on Windows")
+    endif()
+    # Vendored static libraries end up inside the shared core. Their symbols
+    # do not reach the core's consumers: a PRIVATE dependency stops at a
+    # shared library, and aether_wdsp is built with hidden visibility. A test
+    # that calls WDSP directly while linking only aethercore links against
+    # the static core and fails here; go through core/dsp/WdspChannel.h.
+    set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+    set(_aether_core_library_type SHARED)
+    message(STATUS "AetherSDR: libaethercore built SHARED (AETHER_SHARED_CORE)")
+else()
+    set(_aether_core_library_type STATIC)
+endif()
 option(ENABLE_RTL "Enable the experimental receive-only RTL-SDR backend" ON)
 # Which SSB modulator the Hermes-Lite 2 transmit path is BUILT with. There is
 # no runtime switch and there must not be one: two silent transmit paths are
@@ -1574,7 +1595,7 @@ add_subdirectory(third_party/wdsp EXCLUDE_FROM_ALL)
 # their feature blocks). Qt resources (resources.qrc, DFNR model qrc) stay on
 # the executable: rcc registration runs from the exe's static initializers and
 # is process-global, so core code reading ":/..." keeps working.
-add_library(aethercore STATIC
+add_library(aethercore ${_aether_core_library_type}
     ${CORE_SOURCES}
     ${MODEL_SOURCES}
     ${RNNOISE_SOURCES}