Standard Errors

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. Errors, for an explanation of how errors are generated and handled.

error: The message is error. Errors.
quit: The message is Quit. Quitting.
minibuffer-quit: The message is Quit. This is a subcategory of quit. 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. Sequences Arrays Vectors, and see Text.
arith-error: The message is Arithmetic error. This occurs when trying to perform integer division by zero. Numeric Conversions, and see Arithmetic Operations.
beginning-of-buffer: The message is Beginning of buffer. Character Motion.
buffer-read-only: The message is Buffer is read-only. Read Only Buffers.
circular-list: The message is List contains a loop. This happens when a circular structure is encountered. Circular Objects.
cl-assertion-failed: The message is Assertion failed. This happens when the cl-assert macro fails a test. Assertions.
coding-system-error: The message is Invalid coding system. Lisp and Coding Systems.
cyclic-function-indirection: The message is Symbol's chain of function indirections contains a loop. Function Indirection.
cyclic-variable-indirection: The message is Symbol's chain of variable indirections contains a loop. Variable Aliases.
dbus-error: The message is D-Bus error. Errors and Events.
end-of-buffer: The message is End of buffer. Character Motion.
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. Input Functions.
file-already-exists: This is a subcategory of file-error. Writing to Files.
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. Changing Files.
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. Files.
file-missing: This is a subcategory of file-error. It occurs when an operation attempts to act on a file that is missing. Changing Files.
compression-error: This is a subcategory of file-error, which results from problems handling a compressed file. How Programs Do Loading.
file-locked: This is a subcategory of file-error. File Locks.
file-supersession: This is a subcategory of file-error. Modification Time.
file-notify-error: This is a subcategory of file-error. It happens, when a file could not be watched for changes. File Notifications.
remote-file-error: This is a subcategory of file-error, which results from problems in accessing a remote file. Remote Files. 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. Bugs.
ftp-error: This is a subcategory of remote-file-error, which results from problems in accessing a remote file using ftp. Remote Files.
invalid-function: The message is Invalid function. Function Indirection.
invalid-read-syntax: The message is usually Invalid read syntax. Printed Representation. 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. Regular Expressions.
mark-inactive: The message is The mark is not active now. The Mark.
no-catch: The message is No catch for tag. 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. 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. List Motion, and see Parsing Expressions.
search-failed: The message is Search failed. 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. Constant Variables.
text-read-only: The message is Text is read-only. This is a subcategory of buffer-read-only. Special Properties.
undefined-color: The message is Undefined color. Color Names.
user-error: The message is the empty string. Signaling Errors.
user-search-failed: This is like search-failed, but doesn't trigger the debugger, like user-error. Signaling Errors, and see Searching and Matching. This is used for searching in Info files, see Search Text.
void-function: The message is Symbol's function definition is void. Function Cells.
void-variable: The message is Symbol's value as variable is void. Accessing Variables.
wrong-number-of-arguments: The message is Wrong number of arguments. Argument List.
wrong-type-argument: The message is Wrong type argument. Type Predicates.
unknown-image-type: The message is Cannot determine image type. Images.
inhibited-interaction: The message is User interaction while inhibited. This error is signalled when inhibit-interaction is non-nil and a user interaction function (like read-from-minibuffer) is called.