Diagnostic codes

Every diagnostic has a code, a primary span in a file you own, the expected and actual facts, and a fix when one is known; see check. W-* codes are warnings and never stop a compilation. sexpgpu check <file> --json gives the same as an array.

Reading and evaluating

code	what it means	usual fix
E-READ-001	end of input inside a form or a string	close the bracket or the quote
E-READ-002	an unexpected ) or ]	remove it, or open the form it closes
E-READ-003	a token that is not a number, keyword or symbol	0.5 not .5; : plus a name for a keyword
E-EVAL-001	the program called (error ...)	read the message
E-EVAL-002	an (assert ...) failed	read the message
E-EVAL-003	a name is not bound; a knob used before its defknobs lands here	the fix names the module that defines it, or the nearest name
E-EVAL-004	calling something that is not a function	check the head of the call
E-EVAL-005	a malformed special form, lambda list, or a binding of reserved syntax	use the documented shape; see special forms
E-EVAL-006	an argument of the wrong type, a bad destructuring, a bad dtype keyword	check the operand
E-EVAL-007	integer overflow or division by zero
E-EVAL-010	a keyword argument that is not a keyword, unknown, or has no value	the fix lists the accepted keywords
E-EVAL-011	the wrong number of arguments
E-EVAL-030	a file requires itself	move the shared definitions into a third file
E-EVAL-031	a required file cannot be read	paths are relative to the file holding the require
E-EVAL-032	a require path is neither relative nor a package	./name.sx, or sexpgpu/<module>
E-EVAL-033	no such standard module	the fix lists the ones that exist
E-EVAL-034	a require names nothing or is in a local scope	list names, at module top level
E-EVAL-035	a require names what the file does not define	the fix is the nearest name it does
E-EVAL-036	a name bound twice in one file, by two imports or an import and a definition	rename, or import once
E-EVAL-040	recursion deeper than 256 calls	no tail calls; check the base case, or use repeat/reduce
E-EVAL-041	compile-time work budget exceeded or invalid	raise SEXPGPU_EVAL_LIMIT for finite generators

Tensors and staging

code	what it means	usual fix
E-DIM-001	shapes do not fit	the note names both operands as you wrote them
E-DIM-002	dtypes differ, or :x is not a dtype	dtypes are :f32 :bf16 :i32 :i64 :bool
E-DIM-003	a tensor was expected
E-FLOW-001	if on a tensor	select elementwise with (where test then else)
E-FLOW-002	a tensor from another graph	recompute it here
E-FLOW-003	a tensor operation with no graph being traced	tensors exist in prepare, a model, objective, evaluate, an optimizer body, an initializer or curriculum

Models and optimizers

code	what it means	usual fix
E-PARAM-002	defparam outside a model	parameters live inside defmodel
E-PARAM-003	an initializer reads another value	an initializer is closed: shapes, constants, random nodes
E-PARAM-004	a model body does not end in a function	return (lambda (x) ...) last
E-PARAM-005	named on something that is not a model or a parameter
E-PARAM-006	an unknown parameter option, or :numerics other than :high	the options are :tags and :numerics
W-PARAM-001	a model is never bound to a name	bind it with let, or named
E-OPT-001	a selector matches no parameter	check paths with sexpgpu explain, or widen the glob
E-OPT-002	a parameter is in more than one group	narrow one selector with select-not
E-OPT-003	a misplaced or duplicate state, or a state initializer that is not a zero constant	return zeros, zeros-like or a zero full
E-OPT-004	an optimizer body does not end in optimizer-update, or drops a state	return every declared state exactly once
E-OPT-005	a malformed select, group, :groups or :optimizer, or an inner optimizer with :groups	the fix prints the shape
E-OBJ-001	objective does not return one float scalar	reduce the loss; report the parts with metric

The contract

code	what it means	usual fix
E-CONTRACT-001	a required top-level name is missing	the fix writes the form that defines it, (defrun :steps 300 :microbatches 4); see the run file
E-CONTRACT-002	a contract name is the wrong kind of value	the fix writes the form that defines it
E-CONTRACT-003	an unknown keyword in a configuration form, or a bad :precision	the fix lists the accepted ones
E-CONTRACT-004	prepare did not return :inputs and :targets	(list :inputs ... :targets ...)
E-CONTRACT-005	the batch has no such field	the fix lists what the loader declares
E-CONTRACT-010	counter outside prepare	count where records are counted
E-CONTRACT-011	metric in an optimizer body	a diagnostic, or compute it in objective or evaluate
E-CONTRACT-012	a metric's metadata is over what Metrics accepts, runtime keys counted	fewer or shorter keys
E-CONTRACT-013	two defeval passes share a name
E-CONTRACT-014	evaluate or curriculum with no defeval pass	declare a pass
E-CONTRACT-015	a diagnostic without :reduce, with an unknown one, or two reducers for one name	one of :mean :min :max :sum
E-CONTRACT-016	a diagnostics selection that names nothing the file defines	the fix lists the names
E-CONTRACT-017	a metric inside a tap-gradient lambda	report the gradient with diagnostic

Knobs

code	what it means	usual fix
E-KNOB-001	a knob is declared twice
E-KNOB-003	a variant or sweep sets something that is not a knob	the fix lists the knobs
E-KNOB-004	the file declares no such variant	the fix lists the variants
E-KNOB-005	the file declares no such knob	the fix lists the knobs
E-KNOB-006	a duplicate variant, or one after defknobs	declare variants once, before defknobs

Run time and tools

code	what it means	usual fix
E-DP-001 .. E-DP-007	several GPUs or nodes: configuration, rendezvous and resume	see devices
E-MEM-001	the smallest memory plan does not fit on the device; the message names the number and the largest part	fewer rows per microbatch (raise :microbatches), or a device with more memory; see devices
E-FMT-001	the formatter refused its own output	a compiler bug; the file was left as it was
E-INTERNAL-001	the lowered document failed validation	a compiler bug, never the experiment's fault