My Cygwin installation has been upgraded over the years, so could have problematic remnants.
I note the corporate C:\Program Files\McAfee\DLP\Agent\fcagpph64.dll in the mix & don’t understand
_why cygcheck sees the Java DLLs as being in the mix, which seems relevant.
It looks like ldd segfaults under strace, but hangs if run in an xterm, or Cygwin Terminal
When I used Task Manager to kill the ldh process – which didn’t show in ps, I got the following output from ldd

$ ldd  /cygdrive/c/Windows/System32/msvcrt.dll
        ntdll.dll => /cygdrive/c/WINDOWS/SYSTEM32/ntdll.dll (0x7ffd00010000)
        KERNEL32.DLL => /cygdrive/c/WINDOWS/System32/KERNEL32.DLL (0x7ffcfe1a0000)
        KERNELBASE.dll => /cygdrive/c/WINDOWS/System32/KERNELBASE.dll (0x7ffcfdc60000)
        ctiuser.dll => /cygdrive/c/WINDOWS/system32/ctiuser.dll (0x7ffcf4030000)
        msvcrt.dll => /cygdrive/c/WINDOWS/System32/msvcrt.dll (0x7ffcfe6a0000)
        ADVAPI32.dll => /cygdrive/c/WINDOWS/System32/ADVAPI32.dll (0x7ffcfefc0000)
        sechost.dll => /cygdrive/c/WINDOWS/System32/sechost.dll (0x7ffcfff30000)
        RPCRT4.dll => /cygdrive/c/WINDOWS/System32/RPCRT4.dll (0x7ffcfe070000)
        FLTLIB.DLL => /cygdrive/c/WINDOWS/system32/FLTLIB.DLL (0x7ffce5a50000)
        ucrtbase.dll => /cygdrive/c/WINDOWS/System32/ucrtbase.dll (0x7ffcfda00000)
        fcagpph64.dll => /cygdrive/c/Program Files/McAfee/DLP/Agent/fcagpph64.dll (0x7ffcbd240000)
        USER32.dll => /cygdrive/c/WINDOWS/System32/USER32.dll (0x7ffcfe3e0000)
        win32u.dll => /cygdrive/c/WINDOWS/System32/win32u.dll (0x7ffcfdf40000)
        GDI32.dll => /cygdrive/c/WINDOWS/System32/GDI32.dll (0x7ffcffea0000)
        gdi32full.dll => /cygdrive/c/WINDOWS/System32/gdi32full.dll (0x7ffcfd7b0000)
        msvcp_win.dll => /cygdrive/c/WINDOWS/System32/msvcp_win.dll (0x7ffcfd960000)
        SHELL32.dll => /cygdrive/c/WINDOWS/System32/SHELL32.dll (0x7ffcff130000)
        ole32.dll => /cygdrive/c/WINDOWS/System32/ole32.dll (0x7ffcffc90000)
        combase.dll => /cygdrive/c/WINDOWS/System32/combase.dll (0x7ffcff930000)
        SHLWAPI.dll => /cygdrive/c/WINDOWS/System32/SHLWAPI.dll (0x7ffcff0d0000)
        WS2_32.dll => /cygdrive/c/WINDOWS/System32/WS2_32.dll (0x7ffcfe740000)
        OLEAUT32.dll => /cygdrive/c/WINDOWS/System32/OLEAUT32.dll (0x7ffcffdc0000)
        WINSPOOL.DRV => /cygdrive/c/WINDOWS/SYSTEM32/WINSPOOL.DRV (0x7ffce6580000)
        VERSION.dll => /cygdrive/c/WINDOWS/SYSTEM32/VERSION.dll (0x7ffcf2ed0000)
        IMM32.DLL => /cygdrive/c/WINDOWS/System32/IMM32.DLL (0x7ffcfea00000)
        SspiCli.dll => /cygdrive/c/WINDOWS/SYSTEM32/SspiCli.dll (0x7ffcfd5e0000)
        bcryptPrimitives.dll => /cygdrive/c/WINDOWS/System32/bcryptPrimitives.dll (0x7ffcfd720000)
        ntmarta.dll => /cygdrive/c/WINDOWS/SYSTEM32/ntmarta.dll (0x7ffcfc800000)
        api-ms-win-core-fibers-l1-1-0.dll => not found
        api-ms-win-core-file-l1-1-0.dll => /cygdrive/c/Program Files/Java/jdk-11.0.10/bin/api-ms-win-core-file-l1-1-0.dll (?)
        api-ms-win-core-handle-l1-1-0.dll => /cygdrive/c/Program Files/Java/jdk-11.0.10/bin/api-ms-win-core-handle-l1-1-0.dll (?)
        api-ms-win-core-heap-l1-1-0.dll => /cygdrive/c/Program Files/Java/jdk-11.0.10/bin/api-ms-win-core-heap-l1-1-0.dll (?)
        api-ms-win-core-localization-l1-2-0.dll => /cygdrive/c/Program Files/Java/jdk-11.0.10/bin/api-ms-win-core-localization-l1-2-0.dll (?)
        api-ms-win-core-libraryloader-l1-2-0.dll => not found
        api-ms-win-core-memory-l1-1-0.dll => /cygdrive/c/Program Files/Java/jdk-11.0.10/bin/api-ms-win-core-memory-l1-1-0.dll (?)
        api-ms-win-core-namedpipe-l1-1-0.dll => /cygdrive/c/Program Files/Java/jdk-11.0.10/bin/api-ms-win-core-namedpipe-l1-1-0.dll (?)
        api-ms-win-core-processenvironment-l1-1-0.dll => /cygdrive/c/Program Files/Java/jdk-11.0.10/bin/api-ms-win-core-processenvironment-l1-1-0.dll (?)
        api-ms-win-core-processthreads-l1-1-0.dll => /cygdrive/c/Program Files/Java/jdk-11.0.10/bin/api-ms-win-core-processthreads-l1-1-0.dll (?)
        api-ms-win-core-profile-l1-1-0.dll => /cygdrive/c/Program Files/Java/jdk-11.0.10/bin/api-ms-win-core-profile-l1-1-0.dll (?)
        api-ms-win-core-string-l1-1-0.dll => /cygdrive/c/Program Files/Java/jdk-11.0.10/bin/api-ms-win-core-string-l1-1-0.dll (?)
        api-ms-win-core-synch-l1-1-0.dll => /cygdrive/c/Program Files/Java/jdk-11.0.10/bin/api-ms-win-core-synch-l1-1-0.dll (?)
        api-ms-win-core-synch-l1-2-0.dll => /cygdrive/c/Program Files/Java/jdk-11.0.10/bin/api-ms-win-core-synch-l1-2-0.dll (?)
        api-ms-win-core-sysinfo-l1-1-0.dll => /cygdrive/c/Program Files/Java/jdk-11.0.10/bin/api-ms-win-core-sysinfo-l1-1-0.dll (?)
        api-ms-win-core-util-l1-1-0.dll => /cygdrive/c/Program Files/Java/jdk-11.0.10/bin/api-ms-win-core-util-l1-1-0.dll (?)


$ cygcheck /cygdrive/c/Windows/System32/msvcrt.dll
c:\Windows\System32\msvcrt.dll
  C:\WINDOWS\system32\ntdll.dll
  C:\Program Files\Java\jdk-11.0.10\bin\api-ms-win-core-console-l1-1-0.dll
  C:\Program Files\Java\jdk-11.0.10\bin\api-ms-win-core-console-l1-2-0.dll
  C:\Program Files\Java\jdk-11.0.10\bin\api-ms-win-core-datetime-l1-1-0.dll
  C:\Program Files\Java\jdk-11.0.10\bin\api-ms-win-core-debug-l1-1-0.dll
  C:\Program Files\Java\jdk-11.0.10\bin\api-ms-win-core-errorhandling-l1-1-0.dll
  C:\Program Files\Java\jdk-11.0.10\bin\api-ms-win-core-file-l1-1-0.dll
  C:\Program Files\Java\jdk-11.0.10\bin\api-ms-win-core-handle-l1-1-0.dll
  C:\Program Files\Java\jdk-11.0.10\bin\api-ms-win-core-heap-l1-1-0.dll
  C:\Program Files\Java\jdk-11.0.10\bin\api-ms-win-core-localization-l1-2-0.dll
  C:\Program Files\Java\jdk-11.0.10\bin\api-ms-win-core-memory-l1-1-0.dll
  C:\Program Files\Java\jdk-11.0.10\bin\api-ms-win-core-namedpipe-l1-1-0.dll
  C:\Program Files\Java\jdk-11.0.10\bin\api-ms-win-core-processenvironment-l1-1-
0.dll
  C:\Program Files\Java\jdk-11.0.10\bin\api-ms-win-core-processthreads-l1-1-0.dl
l
  C:\Program Files\Java\jdk-11.0.10\bin\api-ms-win-core-profile-l1-1-0.dll
  C:\Program Files\Java\jdk-11.0.10\bin\api-ms-win-core-string-l1-1-0.dll
  C:\Program Files\Java\jdk-11.0.10\bin\api-ms-win-core-synch-l1-1-0.dll
  C:\Program Files\Java\jdk-11.0.10\bin\api-ms-win-core-synch-l1-2-0.dll
  C:\Program Files\Java\jdk-11.0.10\bin\api-ms-win-core-sysinfo-l1-1-0.dll
  C:\Program Files\Java\jdk-11.0.10\bin\api-ms-win-core-util-l1-1-0.dll
  C:\WINDOWS\system32\KERNELBASE.dll

# Java is in my PATH but ???

$ strace -o ldd-stce.txt ldd  /cygdrive/c/Windows/System32/msvcrt.dll
Segmentation fault

# ldd-stce.txt
--- Process 23572 loaded C:\Windows\System32\ntdll.dll at 00007ffd00010000
--- Process 23572 loaded C:\Windows\System32\kernel32.dll at 00007ffcfe1a0000
--- Process 23572 loaded C:\Windows\System32\KernelBase.dll at 00007ffcfdc60000
--- Process 23572 loaded C:\Windows\System32\ctiuser.dll at 00007ffcf4030000
--- Process 23572 loaded C:\Windows\System32\psapi.dll at 00007ffcffe90000
--- Process 23572 loaded C:\cygwin64\bin\cygwin1.dll at 00007ffccdec0000
--- Process 23572 loaded C:\Windows\System32\advapi32.dll at 00007ffcfefc0000
--- Process 23572 loaded C:\Windows\System32\msvcrt.dll at 00007ffcfe6a0000
--- Process 23572 loaded C:\Windows\System32\sechost.dll at 00007ffcfff30000
--- Process 23572 loaded C:\Windows\System32\rpcrt4.dll at 00007ffcfe070000
--- Process 23572 loaded C:\Windows\System32\fltLib.dll at 00007ffce5a50000
--- Process 23572 loaded C:\Windows\System32\ucrtbase.dll at 00007ffcfda00000
--- Process 23572 thread 22416 created
    0       0 [main] ldd (23572) **********************************************
1331    1331 [main] ldd (23572) Program name: C:\cygwin64\bin\ldd.exe (windows pid 23572)
  168    1499 [main] ldd (23572) OS version:   Windows NT-10.0
  193    1692 [main] ldd (23572) **********************************************
--- Process 23572 loaded C:\Windows\System32\cryptbase.dll at 00007ffcfcf30000
--- Process 23572 loaded C:\Windows\System32\bcryptprimitives.dll at 00007ffcfd720000
6309    8001 [main] ldd (23572) sigprocmask: 0 = sigprocmask (0, 0x0, 0x7FFCCE199450)
3146   11147 [main] ldd (23572) open_shared: name shared.5, shared 0x1A0000000 (wanted 0x1A0000000), h 0x114, m 0, created 0
  222   11369 [main] ldd (23572) user_heap_info::init: heap base 0xA00000000, heap top 0xA00000000, heap size 0x20000000 (536870912)
  179   11548 [main] ldd (23572) open_shared: name S-1-5-21-2799465626-2441719393-1676202033-1287.1, shared 0x1A1000000 (wanted 0x1A1000000), h 0x110, m 1, created 0
  171   11719 [main] ldd (23572) user_info::create: opening user shared for 'S-1-5-21-2799465626-2441719393-1676202033-1287' at 0x1A1000000
  237=1B5B313B324656   11875 [main] ldd (23572) user_info::create: user shared version AB1FCCE8
  230   12105 [main] ldd (23572) fhandler_pipe::create: name \\.\pipe\cygwin-e022582115c10879-23572-sigwait<file://./pipe/cygwin-e022582115c10879-23572-sigwait>, size 11440, mode PIPE_TYPE_MESSAGE
--- Process 23572 created
--- Process 23572 loaded C:\Windows\System32\ntdll.dll at 00007ffd00010000
--- Process 23572 loaded C:\Windows\System32\kernel32.dll at 00007ffcfe1a0000
--- Process 23572 loaded C:\Windows\System32\KernelBase.dll at 00007ffcfdc60000
--- Process 23572 loaded C:\Windows\System32\ctiuser.dll at 00007ffcf4030000
--- Process 23572 loaded C:\Windows\System32\psapi.dll at 00007ffcffe90000
--- Process 23572 loaded C:\cygwin64\bin\cygwin1.dll at 00007ffccdec0000
--- Process 23572 loaded C:\Windows\System32\advapi32.dll at 00007ffcfefc0000
--- Process 23572 loaded C:\Windows\System32\msvcrt.dll at 00007ffcfe6a0000
--- Process 23572 loaded C:\Windows\System32\sechost.dll at 00007ffcfff30000
--- Process 23572 loaded C:\Windows\System32\rpcrt4.dll at 00007ffcfe070000
--- Process 23572 loaded C:\Windows\System32\fltLib.dll at 00007ffce5a50000
--- Process 23572 created
--- Process 23572 loaded C:\Windows\System32\ntdll.dll at 00007ffd00010000
--- Process 23572 loaded C:\Windows\System32\kernel32.dll at 00007ffcfe1a0000
--- Process 23572 loaded C:\Windows\System32\KernelBase.dll at 00007ffcfdc60000
--- Process 23572 loaded C:\Windows\System32\ctiuser.dll at 00007ffcf4030000
--- Process 23572 loaded C:\Windows\System32\psapi.dll at 00007ffcffe90000
--- Process 23572 loaded C:\cygwin64\bin\cygwin1.dll at 00007ffccdec0000
--- Process 23572 loaded C:\Windows\System32\advapi32.dll at 00007ffcfefc0000
--- Process 23572 loaded C:\Windows\System32\msvcrt.dll at 00007ffcfe6a0000
--- Process 23572 loaded C:\Windows\System32\sechost.dll at 00007ffcfff30000
--- Process 23572 loaded C:\Windows\System32\rpcrt4.dll at 00007ffcfe070000
--- Process 23572 loaded C:\Windows\System32\fltLib.dll at 00007ffce5a50000
--- Process 23572 loaded C:\Windows\System32\ucrtbase.dll at 00007ffcfda00000
--- Process 23572 thread 22416 created
    0       0 [main] ldd (23572) **********************************************
1331    1331 [main] ldd (23572) Program name: C:\cygwin64\bin\ldd.exe (windows pid 23572)
  168    1499 [main] ldd (23572) OS version:   Windows NT-10.0
  193    1692 [main] ldd (23572) **********************************************
--- Process 23572 loaded C:\Windows\System32\cryptbase.dll at 00007ffcfcf30000
--- Process 23572 loaded C:\Windows\System32\bcryptprimitives.dll at 00007ffcfd720000
6309    8001 [main] ldd (23572) sigprocmask: 0 = sigprocmask (0, 0x0, 0x7FFCCE199450)
3146   11147 [main] ldd (23572) open_shared: name shared.5, shared 0x1A0000000 (wanted 0x1A0000000), h 0x114, m 0, created 0
  222   11369 [main] ldd (23572) user_heap_info::init: heap base 0xA00000000, heap top 0xA00000000, heap size 0x20000000 (536870912)
  179   11548 [main] ldd (23572) open_shared: name S-1-5-21-2799465626-2441719393-1676202033-1287.1, shared 0x1A1000000 (wanted 0x1A1000000), h 0x110, m 1, created 0
  171   11719 [main] ldd (23572) user_info::create: opening user shared for 'S-1-5-21-2799465626-2441719393-1676202033-1287' at 0x1A1000000
  237=1B5B313B324656   11875 [main] ldd (23572) user_info::create: user shared version AB1FCCE8
  230   12105 [main] ldd (23572) fhandler_pipe::create: name \\.\pipe\cygwin-e022582115c10879-23572-sigwait<file://./pipe/cygwin-e022582115c10879-23572-sigwait>, size 11440, mode PIPE_TYPE_MESSAGE
--- Process 23572 loaded C:\Windows\System32\ucrtbase.dll at 00007ffcfda00000
--- Process 23572 thread 22416 created
    0       0 [main] ldd (23572) **********************************************
1331    1331 [main] ldd (23572) Program name: C:\cygwin64\bin\ldd.exe (windows pid 23572)
  168    1499 [main] ldd (23572) OS version:   Windows NT-10.0
  193    1692 [main] ldd (23572) **********************************************
--- Process 23572 loaded C:\Windows\System32\cryptbase.dll at 00007ffcfcf30000
--- Process 23572 loaded C:\Windows\System32\bcryptprimitives.dll at 00007ffcfd720000
6309    8001 [main] ldd (23572) sigprocmask: 0 = sigprocmask (0, 0x0, 0x7FFCCE199450)
3146   11147 [main] ldd (23572) open_shared: name shared.5, shared 0x1A0000000 (wanted 0x1A0000000), h 0x114, m 0, created 0
  222   11369 [main] ldd (23572) user_heap_info::init: heap base 0xA00000000, heap top 0xA00000000, heap size 0x20000000 (536870912)
  179   11548 [main] ldd (23572) open_shared: name S-1-5-21-2799465626-2441719393-1676202033-1287.1, shared 0x1A1000000 (wanted 0x1A1000000), h 0x110, m 1, created 0
  171   11719 [main] ldd (23572) user_info::create: opening user shared for 'S-1-5-21-2799465626-2441719393-1676202033-1287' at 0x1A1000000
  237=1B5B313B324656   11875 [main] ldd (23572) user_info::create: user shared version AB1FCCE8
  230   12105 [main] ldd (23572) fhandler_pipe::create: name \\.\pipe\cygwin-e022582115c10879-23572-sigwait<file://./pipe/cygwin-e022582115c10879-23572-sigwait>, size 11440, mode PIPE_TYPE_MESSAGE
1472   13577 [main] ldd (23572) fhandler_pipe::create: pipe read handle 0x12C
  139   13716 [main] ldd (23572) fhandler_pipe::create: CreateFile: name \\.\pipe\cygwin-e022582115c10879-23572-sigwait<file://./pipe/cygwin-e022582115c10879-23572-sigwait>
  951   14667 [main] ldd (23572) fhandler_pipe::create: pipe write handle 0x130
  194   14861 [main] ldd (23572) dll_crt0_0: finished dll_crt0_0 initialization
--- Process 23572 loaded C:\Program Files\McAfee\DLP\Agent\fcagpph64.dll at 00007ffcbd240000
--- Process 23572 loaded C:\Windows\System32\user32.dll at 00007ffcfe3e0000
--- Process 23572 loaded C:\Windows\System32\win32u.dll at 00007ffcfdf40000
--- Process 23572 loaded C:\Windows\System32\gdi32.dll at 00007ffcffea0000
--- Process 23572 loaded C:\Windows\System32\gdi32full.dll at 00007ffcfd7b0000
--- Process 23572 loaded C:\Windows\System32\msvcp_win.dll at 00007ffcfd960000
--- Process 23572 loaded C:\Windows\System32\shell32.dll at 00007ffcff130000
--- Process 23572 loaded C:\Windows\System32\ole32.dll at 00007ffcffc90000
--- Process 23572 loaded C:\Windows\System32\combase.dll at 00007ffcff930000
--- Process 23572 loaded C:\Windows\System32\shlwapi.dll at 00007ffcff0d0000
--- Process 23572 loaded C:\Windows\System32\ws2_32.dll at 00007ffcfe740000
--- Process 23572 loaded C:\Windows\System32\oleaut32.dll at 00007ffcffdc0000
--- Process 23572 loaded C:\Windows\System32\winspool.drv at 00007ffce6580000
--- Process 23572 loaded C:\Windows\System32\version.dll at 00007ffcf2ed0000
--- Process 23572 loaded C:\Windows\System32\imm32.dll at 00007ffcfea00000
--- Process 23572 loaded C:\Windows\System32\sspicli.dll at 00007ffcfd5e0000
--- Process 23572 loaded C:\Windows\System32\ntmarta.dll at 00007ffcfc800000
--- Process 23572 thread 18240 created
--- Process 23572 thread 19844 created
--- Process 23572, exception c0000005 at 00007ffccdf47de4
--- Process 23572 thread 22416 exited with status 0x0
--- Process 23572 thread 25044 exited with status 0xc0000005
--- Process 23572 thread 19844 exited with status 0xc0000005
--- Process 23572 exited with status 0xc0000005

From: Jon Turney <jon.turney@dronecode.org.uk>
Sent: Monday, May 22, 2023 6:32 AM
To: Rodney Brown <rbrown@bravurasolutions.com>; cygwin-apps@cygwin.com
Subject: Re: x86_64 ldd hangs running on a DLL

[EXTERNAL EMAIL]

On 18/05/2023 02:46, Rodney Brown via Cygwin wrote:
> $ uname -a
> CYGWIN_NT-10.0-19045 X 3.4.6-1.x86_64 2023-02-14 13:23 UTC x86_64 Cygwin
> $ ldd --version
> ldd (cygwin) 3.4.6
>
> As with "ldd freezes" https://sourceware.org/legacy-ml/cygwin/2015-07/msg00314.html<https://sourceware.org/legacy-ml/cygwin/2015-07/msg00314.html> , cygcheck works,
> not only for Cygwin DLLs and ldd hangs needing the xterm to be closed, though it can interrupted when run
> under strace, or did. Strace now is segfaulting.

What changed to make it start segfaulting?

> Did Corinna's fix for i686 not end up in the x86_64 code?

The claim here seems to be: ldd is broken on x86_64 for all dlls, and
has been since 2015, and nobody has noticed.

While possible, this seems unlikely.

All I can tell you is that it appears to WFM. Perhaps you can provide
some more details?

> $ ldd /usr/bin/cygwin1.dll
> ntdll.dll => /cygdrive/c/WINDOWS/SYSTEM32/ntdll.dll (0x7ffe56090000)
> KERNEL32.DLL => /cygdrive/c/WINDOWS/System32/KERNEL32.DLL (0x7ffe54a90000)
> KERNELBASE.dll => /cygdrive/c/WINDOWS/System32/KERNELBASE.dll (0x7ffe53c40000)
> msvcrt.dll => /cygdrive/c/WINDOWS/System32/msvcrt.dll (0x7ffe55750000)
> advapi32.dll => /cygdrive/c/WINDOWS/System32/advapi32.dll (0x7ffe54d90000)
> sechost.dll => /cygdrive/c/WINDOWS/System32/sechost.dll (0x7ffe549b0000)
> RPCRT4.dll => /cygdrive/c/WINDOWS/System32/RPCRT4.dll (0x7ffe55570000)
> CRYPTBASE.DLL => /cygdrive/c/WINDOWS/SYSTEM32/CRYPTBASE.DLL (0x7ffe53060000)
> bcryptPrimitives.dll => /cygdrive/c/WINDOWS/System32/bcryptPrimitives.dll (0x7ffe53770000)