Improve stderr logging for PostCSS and simlilar

Fixes #7584

2 files changed, 5 insertions, 4 deletions

diff --git a/resources/resource_transformers/babel/babel.go b/resources/resource_transformers/babel/babel.go
index 72a6b485b..c5ab48dd8 100644
--- a/resources/resource_transformers/babel/babel.go
+++ b/resources/resource_transformers/babel/babel.go
@@ -15,11 +15,12 @@ package babel
 
 import (
 	"io"
-	"os"
 	"os/exec"
 	"path/filepath"
 	"strconv"
 
+	"github.com/gohugoio/hugo/common/loggers"
+
 	"github.com/gohugoio/hugo/common/hugo"
 	"github.com/gohugoio/hugo/resources/internal"
 
@@ -157,7 +158,7 @@ func (t *babelTransformation) Transform(ctx *resources.ResourceTransformationCtx
 	cmd := exec.Command(binary, cmdArgs...)
 
 	cmd.Stdout = ctx.To
-	cmd.Stderr = os.Stderr
+	cmd.Stderr = loggers.LoggerToWriterWithPrefix(logger.INFO, "babel")
 	cmd.Env = hugo.GetExecEnviron(t.rs.Cfg)
 
 	stdin, err := cmd.StdinPipe()
diff --git a/resources/resource_transformers/postcss/postcss.go b/resources/resource_transformers/postcss/postcss.go
index 1f2e51fd8..258185a40 100644
--- a/resources/resource_transformers/postcss/postcss.go
+++ b/resources/resource_transformers/postcss/postcss.go
@@ -36,7 +36,6 @@ import (
 	"github.com/gohugoio/hugo/hugofs"
 	"github.com/pkg/errors"
 
-	"os"
 	"os/exec"
 
 	"github.com/mitchellh/mapstructure"
@@ -199,9 +198,10 @@ func (t *postcssTransformation) Transform(ctx *resources.ResourceTransformationC
 	cmd := exec.Command(binary, cmdArgs...)
 
 	var errBuf bytes.Buffer
+	infoW := loggers.LoggerToWriterWithPrefix(logger.INFO, "postcss")
 
 	cmd.Stdout = ctx.To
-	cmd.Stderr = io.MultiWriter(os.Stderr, &errBuf)
+	cmd.Stderr = io.MultiWriter(infoW, &errBuf)
 	cmd.Env = hugo.GetExecEnviron(t.rs.Cfg)
 
 	stdin, err := cmd.StdinPipe()