What causes "could not parse template %s" in ory/hydra?

Open the migration file named in the message and fix the template syntax (balance {{ if }}/{{ end }}, {{ range }})

could not parse template %s

Error message

could not parse template %s

What it means

When a migration file is a template (usingTemplate is true), its content is parsed with Go's text/template (with SQLTemplateFuncs registered). If template.Parse fails on the file bytes, the underlying parse error is wrapped with 'could not parse template %s' naming the migration file path.

Source

Thrown at oryx/popx/migration_content.go:24

import (
	"bytes"
	"text/template"

	"github.com/pkg/errors"

	"github.com/ory/pop/v6"
	"github.com/ory/x/dbal"
)

func ParameterizedMigrationContent(params map[string]interface{}) func(mf Migration, c *pop.Connection, r []byte, usingTemplate bool) (string, error) {
	return func(mf Migration, c *pop.Connection, b []byte, usingTemplate bool) (string, error) {
		content := ""
		if usingTemplate {
			t := template.New("migration")
			t.Funcs(SQLTemplateFuncs)
			t, err := t.Parse(string(b))
			if err != nil {
				return "", errors.Wrapf(err, "could not parse template %s", mf.Path)
			}
			var bb bytes.Buffer
			err = t.Execute(&bb, struct {
				IsSQLite       bool
				IsCockroach    bool
				IsMySQL        bool
				IsMariaDB      bool
				IsPostgreSQL   bool
				DialectDetails *pop.ConnectionDetails
				Parameters     map[string]interface{}
			}{
				IsSQLite:       c.Dialect.Name() == "sqlite3",
				IsCockroach:    c.Dialect.Name() == "cockroach",
				IsMySQL:        c.Dialect.Name() == "mysql",
				IsMariaDB:      c.Dialect.Name() == "mariadb",
				IsPostgreSQL:   dbal.IsPostgresCompatible(c.Dialect.Name()),
				DialectDetails: c.Dialect.Details(),
				Parameters:     params,

View on GitHub (pinned to 4174065ffb)

Solutions

Open the migration file named in the message and fix the template syntax (balance {{ if }}/{{ end }}, {{ range }})
Verify any called functions exist in SQLTemplateFuncs
Escape literal braces that must not be interpreted as template actions
Test the template by running the migration against a dev database to confirm it parses

Example fix

// before (migration.up.sql)
{{ if .IsSQLite }}CREATE TABLE t... 
// after
{{ if .IsSQLite }}CREATE TABLE t...{{ end }}

Defensive patterns

Strategy: validation

Validate before calling

// Pre-validate template syntax of migration files before running migrations
func templateParses(path string) error {
  b, err := os.ReadFile(path)
  if err != nil { return err }
  t := template.New("check").Funcs(popx.SQLTemplateFuncs)
  _, err = t.Parse(string(b))
  return err
}

Prevention

Run a lint step that parses all .sql migrations as templates in CI
Balance every {{ if }}/{{ range }} with {{ end }} before committing
Escape literal '{{' in SQL with a delims change or template comment
Only call functions documented in SQLTemplateFuncs

When it happens

Trigger: A .sql migration containing malformed Go template syntax — e.g. an unclosed {{ if }}, unknown template function, or stray {{ }} — passed through the templated migration path.

Common situations: Typos in template directives like {{ if .IsSQLite }} without an {{ end }}; calling a func not present in SQLTemplateFuncs; editing a templated migration and breaking syntax; copy-pasting SQL containing '{{' sequences.

Related errors

AI-assisted analysis of ory/hydra@4174065ffb (2026-09-03). Data as JSON: /api/errors/d127419827ee8ead. Report an issue: GitHub.