Setup.sh shows ln fail messages when building UE4

[noonchen-ni]

Hi,

I am following this link to build carla on Ubuntu 20.04.

lsb_release -a
LSB Version:    core-11.1.0ubuntu2-noarch:printing-11.1.0ubuntu2-noarch:security-11.1.0ubuntu2-noarch
Distributor ID: Ubuntu
Description:    Ubuntu 20.04.6 LTS
Release:        20.04
Codename:       focal

Everything looks fine until the third step under the Unreal Engine section:

3. Make the build. This may take an hour or two depending on your system.

    ./Setup.sh && ./GenerateProjectFiles.sh && make

and here is the stdout of ./Setup.sh:

> /media/lenovo/ssd/UnrealEngine_4.26$ ./Setup.sh
Registering git hooks... (this will override existing ones!)
ln: failed to create symbolic link 'lib/mono/4.5/Accessibility.dll': Function not implemented
ln: failed to create symbolic link 'lib/mono/4.5/Commons.Xml.Relaxng.dll': Function not implemented

**** ... tons of symbolic errors omitted... ***

ln: failed to create symbolic link 'lib/mono/xbuild/14.0/bin/Microsoft.Build.Utilities.Core.dll': Function not implemented
ln: failed to create symbolic link 'lib/mono/xbuild/14.0/bin/Mono.XBuild.Tasks.dll': Function not implemented
Fixing inconsistent case in filenames.
Setting up Mono
Checking dependencies...
The following file(s) have been modified:
  Engine/Binaries/ThirdParty/Mono/Linux/etc/mono/registry/last-btime
Would you like to overwrite your changes (y/n)? y
Updating dependencies: 100% (1/1), 0.6 MiB cached, done.
Result: 0
Register the engine installation...
Installing a bundled clang toolchain
Toolchain already installed skipping.

Target arch set to: x86_64-unknown-linux-gnu
Building ThirdParty libraries

If you don't see SUCCESS message in the end, then building did not finish properly.
In that case, take a look into /media/lenovo/ssd/UnrealEngine_4.26/Engine/Build/BatchFiles/Linux/BuildThirdParty.log for details.

No third party libs needed to be built locally

**********  SUCCESS ****************
Setup successful.

You may notice my working path is /media/lenovo/ssd/UnrealEngine_4.26, that's because there is not enough space on the system ssd so I put them in another disk. I also try to create a symbolic folder ~/UnrealEngine_4.26 that points to the path above but no veil.

I can ensure that no file is modified after git clone:

> /media/lenovo/ssd/UnrealEngine_4.26$ git status
On branch carla
Your branch is up to date with 'origin/carla'.


It took 3.30 seconds to enumerate untracked files. 'status -uno'
may speed it up, but you have to be careful not to forget to add
new files yourself (see 'git help status').
nothing to commit, working tree clean

> /media/lenovo/ssd/UnrealEngine_4.26$ git log
commit e8c73304f9f3f91ba12c997516deeb2434e4489e (grafted, HEAD -> carla, origin/carla, origin/HEAD)
Author: Jorge Virgos <[email protected]>
Date:   Thu Aug 22 12:07:32 2024 +0200

    Merge pull request #27 from EmmettJZK/Synkrotron/vulkan_memory_index_crash_fix

    Synkrotron/vulkan memory index crash fix

What am I missing here?

[noonchen-ni]

resolved. My file system is exfat which doesn't support symbolic links.