Go version
go version go1.24.5 linux/amd64
Output of go env
in your module/workspace:
AR='ar'
CC='gcc'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='g++'
GCCGO='gccgo'
GO111MODULE=''
GOAMD64='v1'
GOARCH='amd64'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/home/ubuntu/.cache/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/home/ubuntu/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build3272950330=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/tmp/example/go.mod'
GOMODCACHE='/home/ubuntu/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/home/ubuntu/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/home/ubuntu/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.24.5.linux-amd64'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/home/ubuntu/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/home/ubuntu/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.24.5.linux-amd64/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.24.5'
GOWORK=''
PKG_CONFIG='pkg-config'
What did you do?
I tried running go vet
on the following code and expected no errors:
// example1.go
package example
import "fmt"
func ConditionallyFormattedMessage(message string, args ...interface{}) string {
if len(args) == 0 {
return message
} else {
return fmt.Sprintf(message, args...)
}
}
func Example1(arg string) string {
return ConditionallyFormattedMessage(arg)
}
What did you see happen?
Running go vet
on the above code results in a printf problem being reported despite there being none:
$ go vet
# example.com/m
./example1.go:15:46: non-constant format string in call to example.com/m.ConditionallyFormattedMessage
What did you expect to see?
I expected no errors.
Additional context
The above is a minimal reproduction of an issue I'm seeing with methods in the (quite popular) errorx
package such as (*github.com/joomcode/errorx.Type).New
and (*github.com/joomcode/errorx.Type).Wrap
. The errorx
package has a method that is very similar to the ConditionallyFormattedMessage()
function above - ErrorBuilder.WithConditionallyFormattedMessage()
:
https://github.com/joomcode/errorx/blob/3280086cb5400e2900300ba010ddf658fa717fc4/builder.go#L84-L95
which is used by the aforementioned New
and Wrap
methods:
https://github.com/joomcode/errorx/blob/3280086cb5400e2900300ba010ddf658fa717fc4/type.go#L41-L45
https://github.com/joomcode/errorx/blob/3280086cb5400e2900300ba010ddf658fa717fc4/type.go#L60-L65
An alternative reproduction using github.com/joomcode/errorx@v1.2.0
can be seen below:
// example2.go
package example
import "github.com/joomcode/errorx"
func Example2(arg string) *errorx.Error {
return errorx.InternalError.New(arg)
}
$ go vet
# example.com/m
./example2.go:7:34: non-constant format string in call to (*github.com/joomcode/errorx.Type).New
Comment From: gabyhelp
Related Issues
- x/tools/passes/printf: conditionally printf-like functions are treated as printf-like, causing false positives #73485 (closed)
- cmd/vet: printf analyzer cannot analyze anonymous functions #44350
- x/tools/go/analysis/passes/printf: `%#x` recursion is not recognized #73825 (closed)
- x/tools/gopls: doesn't seem to vet text output formatting errors in non-core packages #34059 (closed)
- x/tools/analysis: printf pass should only allow %w in fmt.Errorf #37792 (closed)
- go vet incorrectly recognizes format verb in string #38131 (closed)
- cmd/vet: Formatting string check cannot see through type assertions or varargs #70814 (closed)
- go1.13 errors package #34060 (closed)
- cmd/doc: garbled -src output #37028 (closed)
- cmd/vet: doesn't handle formatting strings in variables #44063
(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)