gohugoio/hugo · error

WebPPictureInit failed\n

Error message

WebPPictureInit failed\n

What it means

Printed by genwebp's encodeNRGBA (webp.c:117) when WebPPictureInit(&pic) returns false. WebPPictureInit zeroes and sets up a WebPPicture struct and should essentially never fail in a correctly built libwebp; failure indicates an ABI mismatch (the C binary was built against a different libwebp header version than the shared library it loaded), a corrupted WebPPicture pointer, or a severely memory-starved process. The function returns NULL and the caller surfaces 'Error encoding NRGBA to WebP' to the host.

Source

Thrown at internal/warpc/genwebp/webp.c:117

} InputMessage;

typedef struct
{
    Header header;
    InputData data;

} OutputMessage;

#define MAX_LINE_LENGTH 4096

static uint8_t *encodeNRGBA(WebPConfig *config, const uint8_t *rgba, int width, int height, int stride, size_t *output_size)
{
    WebPPicture pic;
    WebPMemoryWriter wrt;
    int ok;
    if (!WebPPictureInit(&pic))
    {
        fprintf(stderr, "WebPPictureInit failed\n");
        return NULL;
    }

    pic.use_argb = 1;
    pic.width = width;
    pic.height = height;
    pic.writer = WebPMemoryWrite;
    pic.custom_ptr = &wrt;
    WebPMemoryWriterInit(&wrt);
    ok = WebPPictureImportRGBA(&pic, rgba, stride);
    if (ok)
    {
        ok = WebPEncode(config, &pic);
        if (!ok)
        {
            fprintf(stderr, "WebPEncode failed: %d (%s)\n", pic.error_code, kErrorMessages[pic.error_code]);
        }
    }

View on GitHub (pinned to 52c9bd7908)

Solutions

1. Rebuild the Hugo binary (and its bundled genwebp) from source against the libwebp now present at runtime, or pin libwebp to the version Hugo was built with.
2. Run `ldd` on the genwebp executable to confirm which libwebp it resolves and that the path matches the build-time expectation.
3. If shipping a static build, ensure libwebp is statically linked to remove the runtime mismatch class entirely.
4. In containers, pin the libwebp package version and rebuild the image when bumping it.
5. Free memory / raise cgroup limits if the box is genuinely OOM.

Example fix

# before: system libwebp updated, Hugo's bundled worker now mismatches
$ hugo build  # WebPPictureInit failed at runtime

# after: rebuild genwebp against the current libwebp, or link statically
go build -tags netgo -ldflags '-linkmode external' ./...
# or in the Hugo Makefile / build script:
CGO_LDFLAGS="-static" go build

// In the host: verify the genwebp binary resolves the expected libwebp before use.
func checkLibwebp(ctx context.Context, bin string) error {
    out, err := exec.CommandContext(ctx, "ldd", bin).CombinedOutput()
    if err != nil { return err }
    if !bytes.Contains(out, []byte("libwebp")) {
        return fmt.Errorf("genwebp does not link libwebp as expected")
    }
    return nil
}

When it happens

Trigger: genwebp was built/linked against one libwebp version but at runtime resolves a different version (e.g. system libwebp updated underneath the Hugo binary), the WebPPicture struct layout differs between compile-time headers and runtime library, or memory allocation inside libwebp failed during init.

Common situations: Hugo binary moved between machines with incompatible libwebp, a distro upgrade replaced libwebp without rebuilding Hugo's C workers, dynamic linking picks up LD_LIBRARY_PATH override, or a container image layered an incompatible libwebp on top of the Hugo base image.

Related errors

• WebPEncode failed: %d (%s)\n
• WebPAnimEncoderAssemble failed\n
• WebPPictureImportRGBA failed: %d (%s)\n
• Error creating WebPAnimEncoder\n
• WebPPictureImportRGBA failed\n

AI-assisted analysis of gohugoio/hugo@52c9bd7908 (2026-08-09). Data as JSON: /api/errors/df5a9ebb639a9209. Report an issue: GitHub.