Here is a list of the more important error symbols in standard Emacs, grouped by concept. The list includes each symbol’s message and a cross reference to a description of how the error can occur.
Each error symbol has a set of parent error conditions that is a
list of symbols. Normally this list includes the error symbol itself
and the symbol error
. Occasionally it includes additional
symbols, which are intermediate classifications, narrower than
error
but broader than a single error symbol. For example, all
the errors in accessing files have the condition file-error
. If
we do not say here that a certain error symbol has additional error
conditions, that means it has none.
As a special exception, the error symbols quit
and
minibuffer-quit
don’t have the condition error
, because
quitting is not considered an error.
Most of these error symbols are defined in C (mainly data.c),
but some are defined in Lisp. For example, the file userlock.el
defines the file-locked
and file-supersession
errors.
Several of the specialized Lisp libraries distributed with Emacs
define their own error symbols. We do not attempt to list of all
those here.
See Errors, for an explanation of how errors are generated and handled.
error
The message is ‘error’. See Errors.
quit
The message is ‘Quit’. See Quitting.
minibuffer-quit
The message is ‘Quit’. This is a subcategory of quit
.
See Quitting.
args-out-of-range
The message is ‘Args out of range’. This happens when trying to access an element beyond the range of a sequence, buffer, or other container-like object. See Sequences, Arrays, and Vectors, and see Text.
arith-error
The message is ‘Arithmetic error’. This occurs when trying to perform integer division by zero. See Numeric Conversions, and see Arithmetic Operations.
beginning-of-buffer
The message is ‘Beginning of buffer’. See Motion by Characters.
buffer-read-only
The message is ‘Buffer is read-only’. See Read-Only Buffers.
circular-list
The message is ‘List contains a loop’. This happens when a circular structure is encountered. See Read Syntax for Circular Objects.
cl-assertion-failed
The message is ‘Assertion failed’. This happens when the
cl-assert
macro fails a test. See Assertions in Common Lisp
Extensions.
coding-system-error
The message is ‘Invalid coding system’. See Coding Systems in Lisp.
cyclic-function-indirection
The message is ‘Symbol's chain of function indirections contains a loop’. See Symbol Function Indirection.
cyclic-variable-indirection
The message is ‘Symbol's chain of variable indirections contains a loop’. See Variable Aliases.
dbus-error
The message is ‘D-Bus error’. See Errors and Events in D-Bus integration in Emacs.
end-of-buffer
The message is ‘End of buffer’. See Motion by Characters.
end-of-file
The message is ‘End of file during parsing’. Note that this is
not a subcategory of file-error
, because it pertains to the
Lisp reader, not to file I/O. See Input Functions.
file-already-exists
This is a subcategory of file-error
. See Writing to Files.
permission-denied
This is a subcategory of file-error
, which occurs when the OS
doesn’t allow Emacs to access a file or a directory for some reason.
file-date-error
This is a subcategory of file-error
. It occurs when
copy-file
tries and fails to set the last-modification time of
the output file. See Changing File Names and Attributes.
file-error
We do not list the error-strings of this error and its subcategories,
because the error message is normally constructed from the data items
alone when the error condition file-error
is present. Thus,
the error-strings are not very relevant. However, these error symbols
do have error-message
properties, and if no data is provided,
the error-message
property is used. See Files.
file-missing
This is a subcategory of file-error
. It occurs when an
operation attempts to act on a file that is missing. See Changing File Names and Attributes.
compression-error
This is a subcategory of file-error
, which results from
problems handling a compressed file. See How Programs Do Loading.
file-locked
This is a subcategory of file-error
. See File Locks.
file-supersession
This is a subcategory of file-error
. See Buffer Modification Time.
file-notify-error
This is a subcategory of file-error
. It happens, when a file
could not be watched for changes. See Notifications on File Changes.
remote-file-error
This is a subcategory of file-error
, which results from
problems in accessing a remote file. See Remote Files in The
GNU Emacs Manual. Often, this error appears when timers, process
filters, process sentinels or special events in general try to access
a remote file, and collide with another remote file operation. In
general it is a good idea to write a bug report.
See Bugs in The GNU Emacs Manual.
ftp-error
This is a subcategory of remote-file-error
, which results from
problems in accessing a remote file using ftp. See Remote Files in The GNU Emacs Manual.
invalid-function
The message is ‘Invalid function’. See Symbol Function Indirection.
invalid-read-syntax
The message is usually ‘Invalid read syntax’. See Printed Representation and Read Syntax. This error can also be raised by commands like
eval-expression
when there’s text following an expression. In
that case, the message is ‘Trailing garbage following expression’.
invalid-regexp
The message is ‘Invalid regexp’. See Regular Expressions.
mark-inactive
The message is ‘The mark is not active now’. See The Mark.
no-catch
The message is ‘No catch for tag’. See Explicit Nonlocal Exits: catch
and throw
.
range-error
The message is Arithmetic range error
.
overflow-error
The message is ‘Arithmetic overflow error’. This is a subcategory
of range-error
.
This can happen with integers exceeding the integer-width
limit.
See Integer Basics.
scan-error
The message is ‘Scan error’. This happens when certain syntax-parsing functions find invalid syntax or mismatched parentheses. Conventionally raised with three argument: a human-readable error message, the start of the obstacle that cannot be moved over, and the end of the obstacle. See Moving over Balanced Expressions, and see Parsing Expressions.
search-failed
The message is ‘Search failed’. See Searching and Matching.
setting-constant
The message is ‘Attempt to set a constant symbol’. This happens
when attempting to assign values to nil
, t
,
most-positive-fixnum
, most-negative-fixnum
, and keyword
symbols. It also happens when attempting to assign values to
enable-multibyte-characters
and some other symbols whose direct
assignment is not allowed for some reason. See Variables that Never Change.
text-read-only
The message is ‘Text is read-only’. This is a subcategory of
buffer-read-only
. See Properties with Special Meanings.
undefined-color
The message is ‘Undefined color’. See Color Names.
user-error
The message is the empty string. See How to Signal an Error.
user-search-failed
This is like ‘search-failed’, but doesn’t trigger the debugger, like ‘user-error’. See How to Signal an Error, and see Searching and Matching. This is used for searching in Info files, see Search Text in Info.
void-function
The message is ‘Symbol's function definition is void’. See Accessing Function Cell Contents.
void-variable
The message is ‘Symbol's value as variable is void’. See Accessing Variable Values.
wrong-number-of-arguments
The message is ‘Wrong number of arguments’. See Features of Argument Lists.
wrong-type-argument
The message is ‘Wrong type argument’. See Type Predicates.
unknown-image-type
The message is ‘Cannot determine image type’. See Images.
inhibited-interaction
The message is ‘User interaction while inhibited’. This error is
signaled when inhibit-interaction
is non-nil
and a user
interaction function (like read-from-minibuffer
) is called.