fix(ci): fix AMDGPU_TARGETS empty-string bypass in hipblas builds (#9626)

* fix(ci): fix AMDGPU_TARGETS empty-string bypass in hipblas builds

399c1dec wired amdgpu-targets through the backend_build workflow_call
interface, intending the input's default value to cover matrix entries
that don't specify targets. However, GitHub Actions only applies a
workflow_call input default when the caller omits the input entirely.
When backend.yml passes `amdgpu-targets: ${{ matrix.amdgpu-targets }}`
and the matrix entry has no amdgpu-targets key, the expression evaluates
to an empty string, which is treated as an explicit value — bypassing
the default. The result is Docker receiving AMDGPU_TARGETS="" which in
turn causes Make's ?= default to be skipped (since the variable is
already set in the environment, even to empty), and cmake gets
-DAMDGPU_TARGETS= with no targets, so the HIP backend compiles for an
indeterminate target rather than the intended GPU list.

Fix this at two levels:

1. backend.yml: use a || fallback in the expression so that an undefined
   matrix.amdgpu-targets never reaches the reusable workflow as an empty
   string. The target list is the canonical default and lives here.

2. backend_build.yml: remove the now-misleading default value from the
   input declaration. The default never fired due to the above bug, so
   keeping it implied a guarantee that didn't exist.

3. backend/cpp/llama-cpp/Makefile: add an explicit $(error ...) guard
   after the ?= assignment so that if AMDGPU_TARGETS is empty (whether
   from environment or any future CI wiring mistake) the build fails
   immediately with a clear message rather than silently producing a
   binary compiled for an unknown GPU target.

Assisted-by: Claude Code:claude-sonnet-4-6
Signed-off-by: Russell Sim <rsl@simopolis.xyz>

* fix(build): plumb AMDGPU_TARGETS through to Docker builds

The docker-build-backend Makefile macro and Dockerfile.golang did not
pass AMDGPU_TARGETS to the inner make invocation, so hipblas builds
always used the backend Makefile's hardcoded default GPU targets
regardless of what was specified via environment or CI inputs.

Signed-off-by: Russell Sim <rsl@simopolis.xyz>

---------

Signed-off-by: Russell Sim <rsl@simopolis.xyz>

.github/workflows/backend.yml

@@ -30,7 +30,7 @@ jobs:
       skip-drivers: ${{ matrix.skip-drivers }}
       context: ${{ matrix.context }}
       ubuntu-version: ${{ matrix.ubuntu-version }}
-      amdgpu-targets: ${{ matrix.amdgpu-targets }}
+      amdgpu-targets: ${{ matrix.amdgpu-targets || 'gfx908,gfx90a,gfx942,gfx950,gfx1030,gfx1100,gfx1101,gfx1102,gfx1151,gfx1200,gfx1201' }}
     secrets:
       dockerUsername: ${{ secrets.DOCKERHUB_USERNAME }}
       dockerPassword: ${{ secrets.DOCKERHUB_PASSWORD }}

.github/workflows/backend_build.yml

@@ -61,7 +61,7 @@ on:
       amdgpu-targets:
         description: 'AMD GPU targets for ROCm/HIP builds'
         required: false
-        default: 'gfx908,gfx90a,gfx942,gfx950,gfx1030,gfx1100,gfx1101,gfx1102,gfx1151,gfx1200,gfx1201'
+        default: ''
         type: string
     secrets:
       dockerUsername:

.github/workflows/backend_pr.yml

@@ -53,6 +53,7 @@ jobs:
       skip-drivers: ${{ matrix.skip-drivers }}
       context: ${{ matrix.context }}
       ubuntu-version: ${{ matrix.ubuntu-version }}
+      amdgpu-targets: ${{ matrix.amdgpu-targets || 'gfx908,gfx90a,gfx942,gfx950,gfx1030,gfx1100,gfx1101,gfx1102,gfx1151,gfx1200,gfx1201' }}
     secrets:
       quayUsername: ${{ secrets.LOCALAI_REGISTRY_USERNAME }}
       quayPassword: ${{ secrets.LOCALAI_REGISTRY_PASSWORD }}