install: let UNSLOTH_TORCH_INDEX_FAMILY / _URL override CUDA wheel detection

install.ps1

@@ -1939,6 +1939,17 @@ exit 0
     # Mirrors Get-PytorchCudaTag in setup.ps1.
     function Get-TorchIndexUrl {
         $baseUrl = if ($env:UNSLOTH_PYTORCH_MIRROR) { $env:UNSLOTH_PYTORCH_MIRROR.TrimEnd('/') } else { "https://download.pytorch.org/whl" }
+        # Explicit pin -- skip ALL GPU probing when the caller names the wheel index
+        # (headless / CI / cross-install). Matches install.sh::get_torch_index_url and
+        # install_python_stack.py: UNSLOTH_TORCH_INDEX_URL wins (full URL, verbatim);
+        # UNSLOTH_TORCH_INDEX_FAMILY is the convenience leaf (cpu, cu128, rocm6.4, ...)
+        # appended to the mirror base so UNSLOTH_PYTORCH_MIRROR is still honoured.
+        if (-not [string]::IsNullOrWhiteSpace($env:UNSLOTH_TORCH_INDEX_URL)) {
+            return $env:UNSLOTH_TORCH_INDEX_URL.Trim().TrimEnd('/')
+        }
+        if (-not [string]::IsNullOrWhiteSpace($env:UNSLOTH_TORCH_INDEX_FAMILY)) {
+            return "$baseUrl/$($env:UNSLOTH_TORCH_INDEX_FAMILY.Trim().Trim('/'))"
+        }
         if (-not $NvidiaSmiExe) { return "$baseUrl/cpu" }
         try {
             $output = Invoke-NvidiaSmiBounded $NvidiaSmiExe
@@ -2016,6 +2027,11 @@ exit 0
         } catch { return $null }
     }
 
+    # An explicit UNSLOTH_TORCH_INDEX_URL / _FAMILY pin is authoritative: the AMD
+    # ROCm reroute below must not rewrite it (e.g. a deliberate cpu pin on an AMD
+    # host, or a pinned ROCm family we already resolved in Get-TorchIndexUrl).
+    $TorchIndexPinned = (-not [string]::IsNullOrWhiteSpace($env:UNSLOTH_TORCH_INDEX_URL)) -or `
+                        (-not [string]::IsNullOrWhiteSpace($env:UNSLOTH_TORCH_INDEX_FAMILY))
     $TorchIndexUrl = Get-TorchIndexUrl
 
     # ── GPU arch → newest compatible Windows ROCm wheel release ──
@@ -2027,7 +2043,9 @@ exit 0
     # Override with UNSLOTH_ROCM_WINDOWS_MIRROR for air-gapped / mirror installs.
     $ROCmIndexUrl = $null
     $ROCmTorchFloor = $null
-    if (($HasROCm -or $ROCmGfxArch) -and $TorchIndexUrl -like "*/cpu" -and -not $SkipTorch) {
+    $PinnedRocmVisionSpec = $null
+    $PinnedRocmAudioSpec = $null
+    if (-not $TorchIndexPinned -and ($HasROCm -or $ROCmGfxArch) -and $TorchIndexUrl -like "*/cpu" -and -not $SkipTorch) {
         $amdIndexBase = if ($env:UNSLOTH_ROCM_WINDOWS_MIRROR) { $env:UNSLOTH_ROCM_WINDOWS_MIRROR.TrimEnd('/') } else { "https://repo.amd.com/rocm/whl" }
         $archFamilyMap = @{
             "gfx1201" = "gfx120X-all"; "gfx1200" = "gfx120X-all"  # RDNA 4
@@ -2077,6 +2095,30 @@ exit 0
         }
     }
 
+    # An explicit gfx*/rocm pin skips the auto-reroute above, but the generic
+    # CPU/CUDA install below would use torch>=2.4,<2.11 and pull a known-bad wheel
+    # on the gfx115x/gfx120x/rocm>=7.2 indexes (the torch._C._grouped_mm null-ptr
+    # bug). Route a pinned ROCm index through the ROCm install path with the same
+    # 2.11 floor/companions the unpinned reroute derives from the gfx arch.
+    if ($TorchIndexPinned -and -not $ROCmIndexUrl -and -not $SkipTorch) {
+        $_pinLeaf = ($TorchIndexUrl.TrimEnd('/') -split '/')[-1].ToLower()
+        $_pinRocm211 = $false
+        if ($_pinLeaf -match '^rocm(\d+)\.(\d+)') {
+            $_pinRocm211 = ([int]$Matches[1] -gt 7) -or ([int]$Matches[1] -eq 7 -and [int]$Matches[2] -ge 2)
+        }
+        if ($_pinLeaf -like 'gfx*' -or $_pinRocm211) {
+            $ROCmIndexUrl = $TorchIndexUrl
+            $ROCmTorchFloor = "torch>=2.11.0,<2.12.0"
+            $PinnedRocmVisionSpec = "torchvision>=0.26.0,<0.27.0"
+            $PinnedRocmAudioSpec = "torchaudio>=2.11.0,<2.12.0"
+            substep "pinned ROCm index ($_pinLeaf) -- enforcing $ROCmTorchFloor" "Cyan"
+        } elseif ($_pinLeaf -like 'rocm*') {
+            # Older rocm (<=7.1) ships torch <2.11; route via the ROCm path with the
+            # default floor so the pinned family resolves its own wheels.
+            $ROCmIndexUrl = $TorchIndexUrl
+        }
+    }
+
     if ($ROCmIndexUrl) {
         $TorchIndexFamily = "rocm"
     } else {
@@ -2189,8 +2231,8 @@ exit 0
             $torchSpec = if ($ROCmTorchFloor) { $ROCmTorchFloor } else { "torch" }
             # Pin the companions to match $torchSpec; bare names can resolve an
             # ABI-incompatible torchvision/torchaudio on AMD's per-arch index.
-            $visionSpec = if ($ROCmGfxArch -and $torchvisionFloorMap.ContainsKey($ROCmGfxArch)) { $torchvisionFloorMap[$ROCmGfxArch] } else { "torchvision" }
-            $audioSpec = if ($ROCmGfxArch -and $torchaudioFloorMap.ContainsKey($ROCmGfxArch)) { $torchaudioFloorMap[$ROCmGfxArch] } else { "torchaudio" }
+            $visionSpec = if ($PinnedRocmVisionSpec) { $PinnedRocmVisionSpec } elseif ($ROCmGfxArch -and $torchvisionFloorMap -and $torchvisionFloorMap.ContainsKey($ROCmGfxArch)) { $torchvisionFloorMap[$ROCmGfxArch] } else { "torchvision" }
+            $audioSpec = if ($PinnedRocmAudioSpec) { $PinnedRocmAudioSpec } elseif ($ROCmGfxArch -and $torchaudioFloorMap -and $torchaudioFloorMap.ContainsKey($ROCmGfxArch)) { $torchaudioFloorMap[$ROCmGfxArch] } else { "torchaudio" }
             $torchInstallExit = Invoke-InstallCommandRetry -Label "install PyTorch (AMD ROCm)" { uv pip install --python $VenvPython --force-reinstall --index-url $ROCmIndexUrl $torchSpec $visionSpec $audioSpec }
             if ($torchInstallExit -ne 0) {
                 # Transient AMD-index failure: fall back to a CPU base so the install
@@ -2200,7 +2242,11 @@ exit 0
                 # torch (e.g. 2.10.0+rocm on gfx110X/gfx90a) that still satisfies the CPU
                 # torch>= range, so without it uv would keep the ROCm build and only swap
                 # the companions -- a mismatched venv the flavor-repair block won't fix.
-                $torchInstallExit = Invoke-InstallCommandRetry -Label "install PyTorch (CPU fallback)" { uv pip install --python $VenvPython --force-reinstall "torch>=2.4,<2.11.0" torchvision torchaudio --index-url $TorchIndexUrl }
+                # Use an explicit CPU index: in the unpinned AMD path $TorchIndexUrl is
+                # already */cpu, but for a pinned ROCm index it IS the ROCm mirror, so
+                # reusing it here would just retry the failing ROCm index, not fall back.
+                $CpuFallbackIndexUrl = if ($env:UNSLOTH_PYTORCH_MIRROR) { "$($env:UNSLOTH_PYTORCH_MIRROR.TrimEnd('/'))/cpu" } else { "https://download.pytorch.org/whl/cpu" }
+                $torchInstallExit = Invoke-InstallCommandRetry -Label "install PyTorch (CPU fallback)" { uv pip install --python $VenvPython --force-reinstall "torch>=2.4,<2.11.0" torchvision torchaudio --index-url $CpuFallbackIndexUrl }
                 if ($torchInstallExit -ne 0) {
                     Write-Host "[ERROR] Failed to install PyTorch (ROCm and CPU base both failed, exit code $torchInstallExit)" -ForegroundColor Red
                     return (Exit-InstallFailure "Failed to install PyTorch (exit code $torchInstallExit)" $torchInstallExit)
@@ -2310,8 +2356,8 @@ exit 0
                     $rocmSpec = if ($ROCmTorchFloor) { $ROCmTorchFloor } else { "torch" }
                     # Pin companions like the fresh ROCm path (bare names can pull an
                     # ABI-incompatible torchvision/torchaudio from the per-arch index).
-                    $visionSpec = if ($ROCmGfxArch -and $torchvisionFloorMap.ContainsKey($ROCmGfxArch)) { $torchvisionFloorMap[$ROCmGfxArch] } else { "torchvision" }
-                    $audioSpec = if ($ROCmGfxArch -and $torchaudioFloorMap.ContainsKey($ROCmGfxArch)) { $torchaudioFloorMap[$ROCmGfxArch] } else { "torchaudio" }
+                    $visionSpec = if ($PinnedRocmVisionSpec) { $PinnedRocmVisionSpec } elseif ($ROCmGfxArch -and $torchvisionFloorMap -and $torchvisionFloorMap.ContainsKey($ROCmGfxArch)) { $torchvisionFloorMap[$ROCmGfxArch] } else { "torchvision" }
+                    $audioSpec = if ($PinnedRocmAudioSpec) { $PinnedRocmAudioSpec } elseif ($ROCmGfxArch -and $torchaudioFloorMap -and $torchaudioFloorMap.ContainsKey($ROCmGfxArch)) { $torchaudioFloorMap[$ROCmGfxArch] } else { "torchaudio" }
                     substep "PyTorch flavor mismatch (installed $installedTorchTag, need ROCm) -- reinstalling correct build..." "Yellow"
                     $torchFixExit = Invoke-InstallCommand { uv pip install --python $VenvPython --force-reinstall --index-url $ROCmIndexUrl $rocmSpec $visionSpec $audioSpec }
                     if ($torchFixExit -ne 0) {

install.sh

@@ -1985,6 +1985,28 @@ _has_usable_nvidia_gpu() {
 get_torch_index_url() {
     _base="${UNSLOTH_PYTORCH_MIRROR:-https://download.pytorch.org/whl}"
     _base="${_base%/}"
+    # Explicit override -- skip ALL GPU probing when the caller pins the wheel
+    # index. Headless / container / CI builds (and anyone cross-installing for a
+    # different target) must not let the build host's GPU -- or the lack of one --
+    # decide the wheel family. This is the same "tell the build, don't ask the
+    # hardware" approach the Docker base image and vLLM/SGLang's Dockerfiles take.
+    # UNSLOTH_TORCH_INDEX_URL wins (full URL, verbatim); UNSLOTH_TORCH_INDEX_FAMILY
+    # is the convenience form (cpu, cu124, cu126, cu128, cu130, rocm6.4, ...)
+    # appended to the mirror base so UNSLOTH_PYTORCH_MIRROR is still honoured.
+    if [ -n "${UNSLOTH_TORCH_INDEX_URL:-}" ]; then
+        # Strip ALL trailing slashes (match the Python side's .rstrip("/") and the
+        # Strix mirror handling below) -- a double/triple-slash URL 404s on strict
+        # pip proxies (artifactory, sonatype).
+        _url="${UNSLOTH_TORCH_INDEX_URL}"
+        while [ "${_url%/}" != "$_url" ]; do _url="${_url%/}"; done
+        echo "$_url"; return
+    fi
+    if [ -n "${UNSLOTH_TORCH_INDEX_FAMILY:-}" ]; then
+        _family="${UNSLOTH_TORCH_INDEX_FAMILY}"
+        while [ "${_family#/}" != "$_family" ]; do _family="${_family#/}"; done
+        while [ "${_family%/}" != "$_family" ]; do _family="${_family%/}"; done
+        echo "$_base/$_family"; return
+    fi
     # macOS: always CPU (no CUDA support)
     case "$(uname -s)" in Darwin) echo "$_base/cpu"; return ;; esac
     # Try nvidia-smi -- require the binary to actually list a usable GPU.
@@ -2381,7 +2403,16 @@ _maybe_bootstrap_rocm_wsl() {
     [ -n "$_rw_tmp" ] && rm -f "$_rw_tmp"
     return 0
 }
-_maybe_bootstrap_rocm_wsl || true
+# When the caller pins the wheel index (UNSLOTH_TORCH_INDEX_URL / _FAMILY),
+# honour it everywhere downstream: skip the WSL ROCm bootstrap (which can run
+# sudo + large downloads after probing /dev/dxg) and the Radeon/Strix rerouting
+# below (which would re-probe the GPU and overwrite the pinned URL). A headless /
+# container / CI build must get exactly the index it asked for.
+_torch_index_pinned=false
+if [ -n "${UNSLOTH_TORCH_INDEX_URL:-}" ] || [ -n "${UNSLOTH_TORCH_INDEX_FAMILY:-}" ]; then
+    _torch_index_pinned=true
+fi
+[ "$_torch_index_pinned" = true ] || _maybe_bootstrap_rocm_wsl || true
 
 TORCH_INDEX_URL=$(get_torch_index_url)
 
@@ -2400,16 +2431,23 @@ case "$_torch_index_leaf" in
     *)          export UNSLOTH_TORCH_BACKEND="cuda" ;;
 esac
 
-# rocm7.2 ships torch 2.11.0 -- adjust the constraint to allow it.
+# rocm7.2 and the AMD per-gfx indexes (repo.amd.com/.../gfxNNNN) ship torch
+# 2.11.0 -- adjust the constraint to allow it. This also covers a pinned full-URL
+# or family override (e.g. UNSLOTH_TORCH_INDEX_URL=.../gfx1151) that returns early
+# above and so never hits the Strix reroute that otherwise raises this constraint.
 # All other ROCm tags and CUDA stay within <2.11.0.
 case "$TORCH_INDEX_URL" in
-    */rocm7.2) TORCH_CONSTRAINT="torch>=2.11.0,<2.12.0" ;;
+    */rocm7.2|*/gfx*) TORCH_CONSTRAINT="torch>=2.11.0,<2.12.0" ;;
 esac
 
 # Auto-detect GPU for AMD ROCm based
 # get_torch_index_url must have chosen */rocm*
 # (gfx in rocminfo or amd-smi list). Then require rocminfo "Marketing Name:.*Radeon".
+# Skipped entirely when the index is pinned: an explicit override (even a ROCm
+# one like UNSLOTH_TORCH_INDEX_FAMILY=rocm6.4) must not be rerouted to the
+# Radeon/Strix repos by GPU probing.
 _amd_gpu_radeon=false
+if [ "$_torch_index_pinned" = false ]; then
 case "$TORCH_INDEX_URL" in
     */rocm*)
         if _has_amd_rocm_gpu && command -v rocminfo >/dev/null 2>&1 && \
@@ -2490,6 +2528,7 @@ case "$TORCH_INDEX_URL" in
         fi
         ;;
 esac
+fi  # _torch_index_pinned guard (Radeon + Strix reroute)
 _TAURI_TORCH_INDEX_FAMILY=$(_tauri_torch_index_family "$TORCH_INDEX_URL")
 if [ "$_amd_gpu_radeon" = true ] && [ "$SKIP_TORCH" = false ]; then
     _TAURI_TORCH_INDEX_FAMILY="radeon"