* Studio: keep llama-server discovery from crashing on an access-denied candidate
_find_llama_server_binary probed candidates with Path.is_file(), which raises
PermissionError (WinError 5) when a path exists but is momentarily inaccessible
(antivirus lock, an install replace in flight, an elevated-install ACL),
aborting model validation. Treat a denied-but-present path as the real binary
so discovery returns it; absent paths still skip.
* Retry a transiently locked binary instead of returning a denied path
Returning a still-denied path only moved the PermissionError to the next
is_file() (probe_server_capabilities). Retry briefly so a transient lock
clears and discovery returns an accessible path; on a persistent lock return
nothing rather than a path downstream cannot stat.
* Studio: do not fall back to another llama-server when a pinned one is locked
A denied LLAMA_SERVER_PATH made discovery skip the explicit pin and run a
lower-priority managed or PATH binary, so a load could silently use a stale or
incompatible server. Split the probe into a file/absent/denied status: when the
pinned path exists but stays access-denied, warn and stop rather than falling
back to a different executable.
* Studio: never downgrade past a denied pinned or managed llama-server
Extend the no-fallback rule beyond LLAMA_SERVER_PATH: a present-but-denied
UNSLOTH_LLAMA_CPP_PATH or managed ($STUDIO_HOME/llama.cpp, ~/.unsloth/llama.cpp)
binary now reports temporarily-unavailable instead of silently launching a
lower-priority legacy or PATH server. Shared _scan_pinned/_unavailable helpers;
legacy in-tree and PATH stay genuine fallbacks (a denied candidate there just
continues).
* Studio: let diffusion asset lookup use a locked llama-server path for its dir
DiffusionGemma does not run llama-server; _find_diffusion_assets only needs the
install dir to find the adjacent llama-diffusion-gemma-visual-server. The
no-fallback rule returning None on a transiently locked llama-server therefore
hid an available visual-server and raised 'runner not found'. Add an
include_denied option so diffusion lookup gets the locked path (its dir is all
it needs), while inference keeps the no-denied-path, no-downgrade behavior.
* Studio: report a locked llama-server as temporarily unavailable, not missing
When the pinned/managed binary stays access-denied through the retries, discovery
returns None and load_model raised 'binary not found', a terminal error that
points users at reinstalling rather than retrying a transient AV/install lock.
Reuse include_denied to detect the locked path and raise a distinct
temporarily-unavailable, retry message instead.
* Studio: GGUF preflight treats a locked llama-server as present
The pre-download preflight (and so /api/inference/validate) used the default
discovery, which returns None for a transiently access-denied binary, so it
raised 'binary not found' for a binary that merely needs the lock to clear. Use
include_denied so the existence check counts a locked binary as present; the
load itself still reports a still-locked binary as temporarily unavailable.
cd270e2878