Enum EnvError 

#[non_exhaustive]
pub enum EnvError {
    #[non_exhaustive]
    BothSet {
        var: String,
        path: String,
    },
    #[non_exhaustive]
    ReadFailed {
        var: String,
        path: String,
        source: Error,
    },
    #[non_exhaustive]
    NotAFile {
        var: String,
        path: String,
    },
    #[non_exhaustive]
    FileTooLarge {
        var: String,
        path: String,
    },
    #[non_exhaustive]
    EmptyFile {
        var: String,
        path: String,
    },
    #[non_exhaustive]
    NextWithoutCurrent {
        var: String,
    },
    #[non_exhaustive]
    Several {
        errors: Vec<EnvError>,
    },
}

Available on crate feature env only.

A problem loading a secret from the environment.

Debug and Display never include a secret’s value — only variable names and file paths, neither of which is secret itself.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

#[non_exhaustive]

BothSet

var and <var>_FILE were both set. Ambiguous on purpose: silently preferring one would hide the other from an operator who set both by mistake.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

var: String

The plain variable name (already fully qualified, e.g. with its oauth_config_from_env prefix applied).

path: String

The path named by <var>_FILE, not the file’s contents.

#[non_exhaustive]

ReadFailed

<var>_FILE named a file that could not be read.

Display names the variable and path only; the I/O failure is the error’s source, not part of its text, so a reporter that walks the source chain (anyhow, for one) prints the cause once rather than twice. oauth_config_from_env appends it to the problem text itself.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

var: String

The plain variable name.

path: String

The path that failed to read.

source: Error

The underlying I/O failure.

#[non_exhaustive]

NotAFile

<var>_FILE names something other than a regular file — a directory, a FIFO, a device such as /dev/zero — which is refused before it is opened: reading one could block startup forever or never end.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

var: String

The plain variable name.

path: String

The path named by <var>_FILE.

#[non_exhaustive]

FileTooLarge

The file named by <var>_FILE is larger than MAX_SECRET_FILE_BYTES (64 KiB). No secret or config value is anywhere near that size; such a file is the wrong file. At most one byte past the limit is read.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

var: String

The plain variable name.

path: String

The path named by <var>_FILE.

#[non_exhaustive]

EmptyFile

The file named by <var>_FILE was read successfully but was empty (or all whitespace). Unlike a blank VAR, this is an error rather than “unset”: a secrets-mount file that exists but is empty is far more likely a provisioning mistake than an intentional absence.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

var: String

The plain variable name.

path: String

The path that was empty.

#[non_exhaustive]

NextWithoutCurrent

static_tokens_from_env: <var>_NEXT (or <var>_NEXT_FILE) is set but <var> (and <var>_FILE) is not. A next key with no current one is a half-done rotation — promote the next key into <var> — and is refused rather than read as the only key.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

var: String

The plain (current-key) variable name.

#[non_exhaustive]

Several

Several variables failed to load at once (from static_tokens_from_env, the current and the next key both), so every problem is reported in one run. Display joins theirs with "; ".

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

errors: Vec<EnvError>

Every failure, in the order the variables were read.

Trait Implementations

impl Debug for EnvError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for EnvError

fn fmt(&self, __formatter: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Error for EnvError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.