Undefined Symbols For Architecture X86 64 Macos

Nov 09, 2020 Expected resolution: The issue is fixed in 2020.2.0b14 and 2021.1.0a9. Known issue: macOS Apple silicon standalone player builds don't launch on Apple silicon devkits running macOS Big Sur beta 6. Another way can be to run gcc -ljpeg, if you get 'ld: library not found for -ljpeg' it means that gcc has not found the library (but it don't mean that it's not installed), if you get something like 'Undefined symbols: 'main', referenced from.' It means that libjpeg has been found.

Undefined Symbols For Architecture X86 64 Macos Iso
Undefined Symbols For Architecture X86 64 Macos Operating System
Undefined Symbols For Architecture X86_64 Macos
Undefined Symbols For Architecture X86 64 Macos Installer

Requirements¶

Linux or macOS with Python ≥ 3.6
PyTorch ≥ 1.6 and torchvision that matches the PyTorch installation.Install them together at pytorch.org to make sure of this
OpenCV is optional but needed by demo and visualization

Build Detectron2 from Source¶

gcc & g++ ≥ 5.4 are required. ninja is recommended for faster build.After having them, run:

To rebuild detectron2 that’s built from a local clone, use rm-rfbuild/**/*.so to clean theold build first. You often need to rebuild detectron2 after reinstalling PyTorch.

Install Pre-Built Detectron2 (Linux only)¶

Choose from this table to install v0.3 (Nov 2020):

CUDA	torch 1.7	torch 1.6	torch 1.5
11.0	install
10.2	install	install	install
10.1	install	install	install
9.2	install	install	install
cpu	install	install	install

Note that:

The pre-built package has to be used with corresponding version of CUDA and the official package of PyTorch.Otherwise, please build detectron2 from source.
New packages are released every few months. Therefore, packages may not contain latest features in the masterbranch and may not be compatible with the master branch of a research project that uses detectron2(e.g. those in projects).

Common Installation Issues¶

Click each issue for its solutions:

Undefined symbols that contains TH,aten,torch,caffe2; Missing torch dynamic libraries; Segmentation fault immediately when using detectron2.

This usually happens when detectron2 or torchvision is notcompiled with the version of PyTorch you’re running.

If the error comes from a pre-built torchvision, uninstall torchvision and pytorch and reinstall themfollowing pytorch.org. So the versions will match.

If the error comes from a pre-built detectron2, check release notesto see the corresponding pytorch version required for each pre-built detectron2.Or uninstall and reinstall the correct pre-built detectron2.

If the error comes from detectron2 or torchvision that you built manually from source,remove files you built (build/, **/*.so) and rebuild it so it can pick up the version of pytorch currently in your environment.

If you cannot resolve this problem, please include the output of gdb-ex'r'-ex'bt'-ex'quit'--argspython-mdetectron2.utils.collect_envin your issue.

Undefined C++ symbols (e.g. `GLIBCXX`) or C++ symbols not found.

Usually it's because the library is compiled with a newer C++ compiler but run with an old C++ runtime.

This often happens with old anaconda.Try condaupdatelibgcc. Then rebuild detectron2.

The fundamental solution is to run the code with proper C++ runtime.One way is to use LD_PRELOAD=/path/to/libstdc++.so.

'nvcc not found' or 'Not compiled with GPU support' or 'Detectron2 CUDA Compiler: not available'.

CUDA is not found when building detectron2.You should make sure

print (True,adirectorywithcuda) at the time you build detectron2.

Most models can run inference (but not training) without GPU support. To use CPUs, set MODEL.DEVICE='cpu' in the config.

'invalid device function' or 'no kernel image is available for execution'.

Two possibilities:

You build detectron2 with one version of CUDA but run it with a different version.
To check whether it is the case,use python-mdetectron2.utils.collect_env to find out inconsistent CUDA versions.In the output of this command, you should expect “Detectron2 CUDA Compiler”, “CUDA_HOME”, “PyTorch built with - CUDA”to contain cuda libraries of the same version.
When they are inconsistent,you need to either install a different build of PyTorch (or build by yourself)to match your local CUDA installation, or install a different version of CUDA to match PyTorch.
PyTorch/torchvision/Detectron2 is not built for the correct GPU SM architecture (aka. compute capability).
The architecture included by PyTorch/detectron2/torchvision is available in the “architecture flags” inpython-mdetectron2.utils.collect_env. It must includethe architecture of your GPU, which can be found at developer.nvidia.com/cuda-gpus.
If you’re using pre-built PyTorch/detectron2/torchvision, they have included support for most popular GPUs already.If not supported, you need to build them from source.
When building detectron2/torchvision from source, they detect the GPU device and build for only the device.This means the compiled code may not work on a different GPU device.To recompile them for the correct architecture, remove all installed/compiled files,and rebuild them with the TORCH_CUDA_ARCH_LIST environment variable set properly.For example, exportTORCH_CUDA_ARCH_LIST='6.0;7.0' makes it compile for both P100s and V100s.

Undefined CUDA symbols; Cannot open libcudart.so

The version of NVCC you use to build detectron2 or torchvision doesnot match the version of CUDA you are running with.This often happens when using anaconda's CUDA runtime.

Use python-mdetectron2.utils.collect_env to find out inconsistent CUDA versions.In the output of this command, you should expect “Detectron2 CUDA Compiler”, “CUDA_HOME”, “PyTorch built with - CUDA”to contain cuda libraries of the same version.

When they are inconsistent,you need to either install a different build of PyTorch (or build by yourself)to match your local CUDA installation, or install a different version of CUDA to match PyTorch.

C++ compilation errors from NVCC / NVRTC; 'Unsupported gpu architecture'

Local CUDA/NVCC version has to match the CUDA version of your PyTorch. Both can be found in pythoncollect_env.py.When they are inconsistent, you need to either install a different build of PyTorch (or build by yourself)to match your local CUDA installation, or install a different version of CUDA to match PyTorch.
Local CUDA/NVCC version shall support the SM architecture (a.k.a. compute capability) of your GPU.The capability of your GPU can be found at developer.nvidia.com/cuda-gpus.The capability supported by NVCC is listed at here.If your NVCC version is too old, this can be workaround a lower capability.environment variableTORCH_CUDA_ARCH_LIST to a lower, supported capability.
The combination of NVCC and GCC you use is incompatible. You need to change one of their versions.See here for some valid combinations.Notably, CUDA<=10.1.105 doesn’t support GCC>7.3.
The CUDA/GCC version used by PyTorch can be found by print(torch.__config__.show()).

'ImportError: cannot import name '_C'.

Please build and install detectron2 following the instructions above.

Or, if you are running code from detectron2’s root directory, cd to a different one.Otherwise you may not import the code that you installed.

Any issue on windows.

Detectron2 is continuously built on windows with CircleCI.However we do not provide official support for it.PRs that improves code compatibility on windows are welcome.

ONNX conversion segfault after some 'TraceWarning'.

The ONNX package is compiled with a too old compiler.

Please build and install ONNX from its source code using a compilerwhose version is closer to what’s used by PyTorch (available in torch.__config__.show()).

Installation inside specific environments:¶

Colab: see our Colab Tutorialwhich has step-by-step instructions.
Docker: The official Dockerfile installs detectron2 with a few simple commands.

Go Up to Delphi Compiler Directives (List) Index

Conditional compilation is based on the existence and evaluation of constants, the status of compiler switches, and the definition of conditional symbols.

2Using Conditional Defines for the Compiler Version

Conditional symbols work like Boolean variables: they are either defined (True) or undefined (False). Any valid conditional symbol is treated as false until it has been defined.

You can define a conditional in the following ways:

Use the {$DEFINE} directive to set a specified symbol to True, and the {$UNDEF} directive to set the symbol to False.
Use the -D switch with the command-line compiler (this option is supported by all the Delphi compilers).
Add the symbol to the Conditional Defines field on the Project > Options > Delphi Compiler page.

The conditional directives {$IFDEF}, {$IFNDEF}, {$IF}, {$ELSEIF}, {$ELSE}, {$ENDIF}, and {$IFEND} allow you to compile or suppress code based on the status of a conditional symbol. {$IF} and {$ELSEIF} allow you to base conditional compilation on declared Delphi identifiers. {$IFOPT} compiles or suppresses code depending on whether a specified compiler switch is enabled.

For example, the following Delphi code snippet processes differently depending on whether the DEBUG conditional define is set ({$DEFINE DEBUG}):

Note: Conditional symbols are not Delphi identifiers and cannot be referenced in actual program code. Similarly, Delphi identifiers cannot be referenced in any conditional directives other than {$IF} and {$ELSEIF}.

Note: Conditional definitions are evaluated only when source code is recompiled. If you change a conditional symbol status and then rebuild a project, source code in unchanged units may not be recompiled. Use Project > Build All Projects to ensure that everything in your project reflects the current status of conditional symbols.

Note: If you modify the name of a conditional define in the Project > Options > Delphi Compiler, you need to Build your project (Project > Build <ProjectName> or Shift + F9) for the changes to take effect.

Conditional-directive constructions can be nested up to 32 levels deep. For every {$IFxxx}, the corresponding {$ENDIF} or {$IFEND} must be found within the same source file. Conditional symbols must start with a letter, followed by any combination of letters, digits, and underscores; they can be of any length, but only the first 255 characters are significant.

Predefined Conditionals

The following standard conditional symbols are defined:

Category	Symbol	DCC32	DCC64 Since XE2	DCCOSX Since XE2	DCCOSX64 Since 10.3 Rio Release 2	DCCIOSARM Since XE3	DCCIOS32 Since XE3	DCCAARM In XE5	DCCIOSARM64 Since XE8	DCCLINUX64 Since 10.2 Tokyo	DCCAARM64 Since 10.3 Rio Release 3	Comments
Compiler	DCC	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED
Compiler	VER340 For a list of compiler versions, see Compiler Versions.	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	For Delphi Sydney, compiler version 34.0 has `VER340` defined.
Platform	CONSOLE	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	Defined if an application is being compiled as a console application.
	IOS	not defined	not defined	not defined	not defined	DEFINED	DEFINED	N/A	DEFINED	not defined	not defined	Defined if the target platform is iOS. New in XE4/iOS.
	IOS32	not defined	not defined	not defined	not defined	DEFINED	DEFINED	not defined	not defined	not defined	not defined	Defined if the target platform is iOS32. Since XE8/iOSarm64.
	IOS64	not defined	not defined	not defined	not defined	not defined	not defined	not defined	DEFINED	not defined	not defined	Defined if the target platform is iOS64. Since XE8/iOSarm64.
	NATIVECODE	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	Since Delphi.Net
	MSWINDOWS	DEFINED	DEFINED	not defined	not defined	not defined	not defined	not defined	not defined	not defined	not defined	Indicates that the operating environment is Windows. Use MSWINDOWS to test for any flavor of the Windows platform instead of WIN32.
	WIN32	DEFINED	not defined	not defined	not defined	not defined	not defined	not defined	not defined	not defined	not defined	Target platform is the native 32-bit Windows platform.
	WIN64	not defined	DEFINED	not defined	not defined	not defined	not defined	not defined	not defined	not defined	not defined	Target platform is 64-bit Windows. New in XE2/x64.
	MACOS	not defined	not defined	DEFINED	DEFINED	DEFINED	DEFINED	not defined	DEFINED	not defined	not defined	Target platform is macOS. New in XE2/macOS.
	MACOS32	not defined	not defined	DEFINED	not defined	DEFINED	DEFINED	not defined	not defined	not defined	not defined	Target platform is 32-bit macOS. New in XE2/macOS.
	MACOS64	not defined	not defined	not defined	DEFINED	not defined	not defined	not defined	DEFINED	not defined	not defined	Target platform is 64-bit macOS. New in XE8/macOS.
	LINUX	not defined	not defined	not defined	not defined	not defined	not defined	not defined	not defined	DEFINED	not defined	Since Kylix.
	LINUX32	not defined	not defined	not defined	not defined	not defined	not defined	not defined	not defined	not defined	not defined	Since Kylix.
	LINUX64	not defined	not defined	not defined	not defined	not defined	not defined	not defined	not defined	DEFINED	not defined	New in 10.2
	POSIX	not defined	not defined	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	Since Kylix.
	POSIX32	not defined	not defined	DEFINED	not defined	DEFINED	DEFINED	DEFINED	DEFINED	not defined	not defined	Since Kylix.
	POSIX64	not defined	not defined	not defined	DEFINED	not defined	not defined	not defined	DEFINED	DEFINED	DEFINED	Since Kylix.
	ANDROID	not defined	not defined	not defined	not defined	not defined	not defined	DEFINED	not defined	not defined	DEFINED	Defined if the target platform is Android. New in XE5.
	ANDROID32	not defined	not defined	not defined	not defined	not defined	not defined	DEFINED	not defined	not defined	not defined	Since XE8/iOSarm64.
	ANDROID64	not defined	not defined	not defined	not defined	not defined	not defined	not defined	not defined	not defined	DEFINED	Delphi compiler for Android 64-bit platform. New in 10.3.3.
CPU	CPU386	DEFINED	not defined	DEFINED	DEFINED	not defined	DEFINED	not defined	not defined	note defined	not defined	Indicates that the CPU is an Intel 386 or later.
	CPUX86	DEFINED	not defined	DEFINED	not defined	not defined	DEFINED	not defined	not defined	not defined	not defined	CPU is an Intel 386 or later on any platform. New in XE2/x64.
	CPUX64	not defined	DEFINED	not defined	DEFINED	not defined	not defined	not defined	not defined	DEFINED	not defined	The CPU supports the x86-64 instruction set, and is in a 64-bit environment. New in XE2/x64.
	CPU32BITS	DEFINED	not defined	DEFINED	not defined	DEFINED	DEFINED	DEFINED	not defined	not defined	not defined	The CPU is in a 32-bit environment, such as DCC32.EXE. New in XE8.
	CPU64BITS	not defined	DEFINED	not defined	DEFINED	not defined	not defined	not defined	DEFINED	DEFINED	DEFINED	The CPU is in a 64-bit environment, such as DCC64.EXE. New in XE8.
	CPUARM	not defined	not defined	not defined	not defined	DEFINED	not defined	DEFINED	DEFINED	not defined	DEFINED	Defined if the CPU is based on the ARM architecture, such as the Delphi mobile compiler for the iOS device (DCCIOSARM.EXE). New in XE4/iOS.
	CPUARM32	not defined	not defined	not defined	not defined	DEFINED	not defined	DEFINED	not defined	not defined	not defined	The CPU is in a 32-bit ARM environment, such as DCCIOSARM.EXE. New in XE8.
	CPUARM64	not defined	not defined	not defined	not defined	not defined	not defined	not defined	DEFINED	not defined	DEFINED	The CPU is in a 64-bit ARM environment, such as DCCIOSARM64.EXE. New in XE8.
Availability
	ALIGN_STACK	not defined	not defined	DEFINED	not defined	not defined	DEFINED	not defined	not defined	not defined	not defined	Defined in code that may be shared with the macOS compiler and another compiler on another platform such as Linux that does not have a rigid stack alignment requirement. For more information, see Eli Boling's blog at http://blogs.embarcadero.com/eboling/2009/05/20/5607 . New in XE2/macOS.
	ASSEMBLER	DEFINED	DEFINED	DEFINED	not defined	not defined	DEFINED	not defined	not defined	not defined	not defined	Assembler syntax is accepted.
	AUTOREFCOUNT (*)	not defined	not defined	not defined	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED if 10.2. Not defined since 10.3.	not defined	Defined for compilers that use automatic reference counting, such as the Delphi mobile compilers. New in XE4/iOS. Removed in 10.4 Sydney.
	EXTERNALLINKER	not defined	not defined	not defined	DEFINED	DEFINED	not defined	DEFINED	DEFINED	DEFINED	DEFINED	Defined for compilers that have an external linker and the LLVM code generator; the Delphi mobile compilers have the external ld linker and use LLVM as code generator. New in XE4/iOS.
	UNICODE	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	UNICODE is defined as the default string type.
	CONDITIONALEXPRESSIONS	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	Tests for the use of the $IF directive.
	ELF	not defined	not defined	not defined	not defined	not defined	not defined	not defined	not defined	DEFINED	not defined	Defined when targeting Executable and Linkable Format (ELF) files.
	NEXTGEN (*)	not defined	not defined	not defined	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED if 10.2. Not defined since 10.3.	not defined	Defined for compilers (such as the Delphi mobile compilers) that use 'next-generation' language features, such as 0-based strings. New in XE4/iOS. Removed in 10.4 Sydney.
	PC_MAPPED_EXCEPTIONS	not defined	not defined	DEFINED	not defined	not defined	DEFINED	not defined	not defined	not defined	not defined	Defined when compiling on a platform or for a target platform that uses address maps instead of stack frames to unwind exceptions (such as macOS). New in XE2.
	PIC	never	never	always DEFINED	always DEFINED	always DEFINED	always DEFINED	always DEFINED	always DEFINED	always DEFINED	always DEFINED	Defined for platforms that require Position-Independent Code (PIC), such as macOS.
	UNDERSCOREIMPORTNAME	DEFINED	not defined	DEFINED	not defined	not defined	DEFINED	not defined	not defined	not defined	not defined	Defined for compilers that add a leading underscore (for example, in names of dynamic libraries imported from Mac OS). New in XE4/iOS.
	WEAKREF	not defined	not defined	not defined	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	Defined for compilers that can use weak references (the `[weak]` attribute). New in XE4/iOS.
	WEAKINSTREF (*)	not defined	not defined	not defined	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED if 10.2. Not defined since 10.3.	not defined	Defined when weak references are defined for instances. New in XE4/iOS. Removed in 10.4 Sydney.
	WEAKINTFREF	not defined	not defined	not defined	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	DEFINED	Defined when weak references are defined for interfaces. New in XE4/iOS.

Attention: The symbols followed by an asterisk (*) were defined for Delphi mobile compilers in the past, but they have been removed in RAD Studio 10.4 Sydney as part of the removal of the ARC memory model.

In the table column heads:

DCC32 is the 32-bit Windows Delphi compiler.
DCC64 is the 64-bit Windows Delphi compiler.
DCCOSX is the 32-bit macOS Delphi compiler.
DCCOSX64 is the 64-bit macOS Delphi compiler.
DCCIOSARM is the Delphi compiler for 32-bit iOS Devices.
DCCIOS32 is the Delphi compiler for iOS Simulators.
DCCAARM.EXE is the Delphi compiler for Android devices.
DCCIOSARM64 is the Delphi compiler for 64-bit iOS devices.
DCCLINUX64 is the 64-bit Linux Delphi compiler.
DCCAARM64.EXE is the Delphi compiler for 64-bit Android devices.

Using Conditional Defines for the Compiler Version

For example, to determine the version of the compiler and run-time library that were used to compile your code, you can use {$IF} with the CompilerVersion, RTLVersion and other constants: