macOS install fails with with `use of undeclared identifier 'DT_LNK'` after `v1.18.0`

[walteh]

Problem
running make after ./configure on macOS throws this error referencing src/bindfs.c

bindfs.c:888:57: error: use of undeclared identifier 'DT_LNK'

The change to include DT_LNK was introduced in #160

- if (settings.resolve_symlinks && (st.st_mode & S_IFLNK) == S_IFLNK) {
+ if ((settings.resolve_symlinks && de->d_type == DT_LNK) || readdirplus) {

Steps to reproduce
macOS version: 15.4.1 (24E263)

# install fuse-t
brew install macos-fuse-t/homebrew-cask/fuse-t

# clone 
git clone https://github.com/mpartel/bindfs.git
cd bindfs 

# install
export FUSE_CFLAGS="-I/usr/local/include/fuse -D_FILE_OFFSET_BITS=64"
export FUSE_LIBS="-L/usr/local/lib -lfuse-t -pthread"
./autogen.sh
./configure
make # ❌ failure here
sudo make install

Potential fix
Falling back to a S_ISLINK check when DTLNK is missing seems to fix the problem. Seems like it's worthwhile to keep the DT_LNK check if it's supported to avoid the syscall. I will submit a PR with the changes that are working for me.

#ifdef DT_LNK
        bool is_symlink = de->d_type == DT_LNK;
#else
        bool is_symlink = S_ISLNK(st.st_mode);
#endif

[walteh]

I found a better solution that didn't involve any changes to the code, turns out the FUSE_CFLAGS and FUSE_LIBS environment variables are case sensitive and NEED to be fuse_CFLAGS and fuse_LIBS and I had to add -D_DARWIN_C_SOURCE to the fuse_CFLAGS.

So to install I am using:

export fuse_CFLAGS="-I/usr/local/include/fuse -D_FILE_OFFSET_BITS=64 -D_DARWIN_C_SOURCE"
export fuse_LIBS="-L/usr/local/lib -lfuse-t -pthread"

./autogen.sh
./configure --with-fuse2
make
sudo make install

Note: these flags come from #100 (comment)

[walteh]

Adding another note for other macOS users that end up here. There is also this error that may come up:

Library not loaded: @rpath/libfuse-t.dylib
  Referenced from: <...> /usr/local/bin/bindfs
  Reason: no LC_RPATH's found

Which I was able to get by with

sudo install_name_tool -add_rpath /usr/local/lib /usr/local/bin/bindfs

Not entirely sure, but seems like based on this apple dev thread that it might be related to having SIP enabled. I didn't dive too deep into, just adding for reference.

[udance4ever]

thank you so much for getting to the bottom of this!

just a heads up I had to use -lfuse (not -lfuse-t) (which technically is what is documented for fuse_LIBS in the comment you referenced):

export fuse_CFLAGS="-I/usr/local/include/fuse -D_FILE_OFFSET_BITS=64 -D_DARWIN_C_SOURCE"
export fuse_LIBS="-L/usr/local/lib -lfuse -pthread"

./autogen.sh
./configure --with-fuse2
make
sudo make install

It is possible this is a function of using a kext-less version of fuse-t (which works awesome for squashfuse too!)

[hartwork]

@mpartel could re-open this as unfixed please? To my understanding this needs some form of -D_DARWIN_C_SOURCE or #define DT_LNK 10 or or … in bindfs to fix this for everyone without patching on their side.

[mpartel]

Should be fixed now, thanks!