Qt for HarmonyOS/platform limitations

This page documents known platform limitations of HarmonyOS that affect Qt behavior. These limitations stem from HarmonyOS security policies, missing system features, or deprecated APIs. Each entry includes its confirmation status and a reference to the corresponding public bug report.

Some items below are still under verification with Huawei and may be refined as more information becomes available.

File System & Permissions

chmod() / QFile::setPermissions() not supported

The HarmonyOS security model does not permit

chmod()

or

fchmod()

on existing files. As a result,

QFile::setPermissions()

is not supported on HarmonyOS for existing files and always returns

false

.

Note that operations that set permissions on a freshly created file descriptor

— for example

QFile::copy()

, which uses

fchmod()

internally

on the newly created destination — are unaffected.

Huawei's official response:

Due to security concerns, the system review for this interface was cancelled, and there is no alternative interface.

Status: Confirmed by Huawei.

Impact:

QFile::setPermissions()

is a no-op on HarmonyOS for existing

files.
Reference: QTBUG-146619

symlink() not available for third-party applications

::symlink()

and its ArkTS equivalent

fs.symlink

are unavailable to third-party applications on HarmonyOS.

QFile::link()

and any functionality depending on symbolic links will fail with

EACCES

(error code 13900012).

Huawei's official response:

fs.symlink is currently not available for third-party applications. The official documentation will be updated accordingly.

Status: Confirmed by Huawei.
Workaround: None available at this time.
Reference: QTBUG-146621

stat() returns EACCES on system paths

stat()

returns

EACCES

(errno 13) when called on system paths such as

/bin/sh

on HarmonyOS. This causes

QFileInfo::isFile()

to return

false

for system executables, while

QFileInfo::exists()

and

QFileInfo::isExecutable()

(which use

access()

internally) return

true

. As a consequence,

QStandardPaths::findExecutable()

cannot locate system

executables on HarmonyOS.

Status: Under verification with Huawei.
Reference: QTBUG-146625

open() with trailing slashes does not fail as expected

On Linux,

open("qwe//", O_RDWR|O_CREAT|O_CLOEXEC, 0666)

fails with

EISDIR

because trailing slashes imply a directory path. On HarmonyOS, the trailing slashes are silently stripped and a regular file named

qwe

is created instead. This behavior differs from POSIX expectations.

Status: Not yet confirmed by Huawei.
Reference: QTBUG-146578

fread() incorrectly sets EOF on a non-blocking pipe

When

fread()

is called on a non-blocking pipe file descriptor with no data available, the HarmonyOS libc incorrectly sets the

EOF

flag on the

FILE*

stream.

Status: Not yet confirmed by Huawei.
Reference: QTBUG-146579

Dynamic Linking

MUSL-LDSO cannot load section-header-stripped ELF files

The HarmonyOS MUSL dynamic linker fails to load ELF shared libraries from which the section header table has been stripped. The linker internally depends on

e_shnum

and

e_shoff

fields within the

LOAD_ORDER_RANDOMIZATION

macro and cannot process binaries that omit

the section header.

Huawei's analysis:

Whether these dependencies can be eliminated in the future is still under investigation.

Status: Acknowledged by Huawei. Fix timeline unknown.
Reference: QTBUG-146620

MUSL-LDSO namespace policy prevents dlopen() from writable paths

The HarmonyOS MUSL dynamic linker rejects

dlopen()

for any path under

/data/storage/el2/

, including temporary directories and all paths returned by

QStandardPaths::writableLocation()

(

AppDataLocation

,

AppConfigLocation

,

CacheLocation

). All available namespaces (

moduleNs_default

,

default

,

ndk

) reject these paths with

errno=22 (EINVAL)

. The only paths accessible to

dlopen()

reside under

/data/storage/el1/

, which is read-only at runtime.

Status: Not yet confirmed by Huawei.
Reference: QTBUG-146624

Standard Paths

QStandardPaths constraints on HarmonyOS

The HarmonyOS application sandbox imposes several constraints on

QStandardPaths

:

```
standardLocations()
```
and
```
writableLocation()
```
return identical

 single-path results for all location types, since the sandbox does not expose
 multiple search locations.

```
AppLocalDataLocation
```
maps to HarmonyOS
```
preferencesDir
```
.
The following location types are unsupported and return an empty path:

PublicShareLocation

,

TemplatesLocation

,

StateLocation

,

GenericStateLocation

.

```
QStandardPaths::findExecutable()
```
cannot locate system executables

due to the

stat()

restriction described above.

Status: Under verification with Huawei.
Reference: QTBUG-146625

Application resource directory location

On HarmonyOS, an application's bundled read-only resource directory resides at

&lt;bundleCodeDir&gt;/entry/resources/resfile

. This is the appropriate location for bundled resources such as

.rcc

files. No

QStandardPaths::StandardLocation

currently maps to this path.

Status: Under investigation.
Reference: QTBUG-146626

Font System

No fixed-pitch (monospaced) font provided by default

HarmonyOS does not ship a monospaced (fixed-pitch) system font by default.

QFontDatabase::systemFont(QFontDatabase::FixedFont)

returns a

non-monospaced font as a result.

Huawei confirmed that

NotoSansMono

must be installed by the user

and is not included in the system font set.

Status: Confirmed by Huawei.
Impact: Applications requiring a monospaced font must bundle and register one

explicitly via

QFontDatabase::addApplicationFont()

.

Reference: QTBUG-146623

ArkUI / ArkTS API

XComponentType.NODE deprecated in API version 20

XComponentType.NODE

, which Qt for HarmonyOS uses as the native rendering

surface, has been deprecated since HarmonyOS API version 20. Huawei recommends

migrating to the

ContentSlot

component.

No official porting guide has been provided by Huawei. Relevant documentation:

Status: API deprecated by Huawei.