Fix loopvar behavior change linting error

cmd/check_imap_mailbox_basic/main.go

@@ -70,6 +70,13 @@ func main() {
 	// sufficient work is in place to allow bulk processing if there is
 	// sufficient interest.
 	for i, account := range cfg.Accounts {
+		// Building with `go build -gcflags=all=-d=loopvar=2` identified this
+		// loop as compiling differently with Go 1.22 (per-iteration) loop
+		// semantics.
+		//
+		// As a workaround, we create a new variable for each iteration to
+		// work around potential issues with Go versions prior to Go 1.22.
+		account := account
 
 		logger := cfg.Log.With().
 			Str("username", account.Username).

cmd/check_imap_mailbox_basic/summary.go

@@ -37,6 +37,14 @@ func setSummary(accounts []config.MailAccount, nes *nagios.Plugin) {
 	)
 
 	for _, account := range accounts {
+		// Building with `go build -gcflags=all=-d=loopvar=2` identified this
+		// loop as compiling differently with Go 1.22 (per-iteration) loop
+		// semantics.
+		//
+		// As a workaround, we create a new variable for each iteration to
+		// work around potential issues with Go versions prior to Go 1.22.
+		account := account
+
 		accountSummary := fmt.Sprintf(
 			"* Account: %s%s** Folders: %s%s%s",
 			account.Username,

cmd/check_imap_mailbox_oauth2/main.go

@@ -71,6 +71,13 @@ func main() {
 	// sufficient work is in place to allow bulk processing if there is
 	// sufficient interest.
 	for i, account := range cfg.Accounts {
+		// Building with `go build -gcflags=all=-d=loopvar=2` identified this
+		// loop as compiling differently with Go 1.22 (per-iteration) loop
+		// semantics.
+		//
+		// As a workaround, we create a new variable for each iteration to
+		// work around potential issues with Go versions prior to Go 1.22.
+		account := account
 
 		logger := cfg.Log.With().
 			Str("client_id", account.OAuth2Settings.ClientID).

cmd/check_imap_mailbox_oauth2/summary.go

@@ -37,6 +37,14 @@ func setSummary(accounts []config.MailAccount, nes *nagios.Plugin) {
 	)
 
 	for _, account := range accounts {
+		// Building with `go build -gcflags=all=-d=loopvar=2` identified this
+		// loop as compiling differently with Go 1.22 (per-iteration) loop
+		// semantics.
+		//
+		// As a workaround, we create a new variable for each iteration to
+		// work around potential issues with Go versions prior to Go 1.22.
+		account := account
+
 		accountSummary := fmt.Sprintf(
 			"* Account: %s%s** Folders: %s%s%s",
 			account.Username,

cmd/list-emails/main.go

@@ -88,6 +88,13 @@ func main() {
 
 	// loop over accounts
 	for i, account := range cfg.Accounts {
+		// Building with `go build -gcflags=all=-d=loopvar=2` identified this
+		// loop as compiling differently with Go 1.22 (per-iteration) loop
+		// semantics.
+		//
+		// As a workaround, we create a new variable for each iteration to
+		// work around potential issues with Go versions prior to Go 1.22.
+		account := account
 
 		fmt.Println("Checking account:", account.Name)
 

internal/config/file.go

@@ -30,6 +30,14 @@ func (c *Config) readConfigFile(configFile ...string) ([]byte, error) {
 	var finalErr error
 
 	for _, file := range configFile {
+		// Building with `go build -gcflags=all=-d=loopvar=2` identified this
+		// loop as compiling differently with Go 1.22 (per-iteration) loop
+		// semantics.
+		//
+		// As a workaround, we create a new variable for each iteration to
+		// work around potential issues with Go versions prior to Go 1.22.
+		file := file
+
 		c.Log.Debug().Str("config_file", file).Msg("Attempting to open config file")
 
 		fh, err := os.Open(filepath.Clean(file))