Repository: conan-io/conan-center-index

Issue:
[package] boost/1.79.0: shared build for iOS produces .so instead of .dylib
### Package and Environment Details

* Package Name/Version: **boost/1.79.0**
* Operating System+version: **macOS 12.5.1**
* Compiler+version: **Apple clang 13**
* Conan version: **conan 1.51.3**
* Python version: **Python 3.10.6**


### Conan profile

Configuration (profile_host):
[settings]
arch=armv8
build_type=Release
compiler=apple-clang
compiler.libcxx=libc++
compiler.version=13
os=iOS
os.sdk=iphoneos
os.version=12.0
[options]
boost:shared=True
boost:without_atomic=True
boost:without_chrono=True
boost:without_container=True
boost:without_context=True
boost:without_contract=True
boost:without_coroutine=True
boost:without_date_time=True
boost:without_exception=True
boost:without_fiber=True
boost:without_filesystem=True
boost:without_graph=True
boost:without_graph_parallel=True
boost:without_iostreams=True
boost:without_json=True
boost:without_locale=True
boost:without_log=True
boost:without_math=True
boost:without_mpi=True
boost:without_nowide=True
boost:without_program_options=True
boost:without_python=True
boost:without_random=True
boost:without_regex=True
boost:without_serialization=True
boost:without_stacktrace=True
boost:without_test=True
boost:without_thread=True
boost:without_timer=True
boost:without_type_erasure=True
boost:without_wave=True
[build_requires]
[env]

Configuration (profile_build):
[settings]
arch=x86_64
arch_build=x86_64
build_type=Release
compiler=apple-clang
compiler.libcxx=libc++
compiler.version=13
os=Macos
os_build=Macos
[options]
[build_requires]
[env]

### Steps to reproduce

Build any Boost library as shared. In this example only `system` is built:

    conan install boost/1.79.0@ --build=missing --profile:build=default --profile:host=ios-arm64 -o 'boost/*:shared=True' -o "boost/*:without_atomic=True" -o "boost/*:without_chrono=True" -o "boost/*:without_container=True" -o "boost/*:without_context=True" -o "boost/*:without_contract=True" -o "boost/*:without_coroutine=True" -o "boost/*:without_date_time=True" -o "boost/*:without_exception=True" -o "boost/*:without_fiber=True" -o "boost/*:without_filesystem=True" -o "boost/*:without_graph=True" -o "boost/*:without_graph_parallel=True" -o "boost/*:without_iostreams=True" -o "boost/*:without_json=True" -o "boost/*:without_locale=True" -o "boost/*:without_log=True" -o "boost/*:without_math=True" -o "boost/*:without_mpi=True" -o "boost/*:without_nowide=True" -o "boost/*:without_program_options=True" -o "boost/*:without_python=True" -o "boost/*:without_random=True" -o "boost/*:without_regex=True" -o "boost/*:without_serialization=True" -o "boost/*:without_stacktrace=True" -o "boost/*:without_test=True" -o "boost/*:without_thread=True" -o "boost/*:without_timer=True" -o "boost/*:without_type_erasure=True" -o "boost/*:without_wave=True"

### Logs

<details><summary>Click to expand log</summary>

```
DEBUG :conan_api.py   [176]: INIT: Using config '/Users/kambala/.conan/conan.conf' [2022-08-31 12:43:31,174]
DEBUG :tracer.py      [156]: CONAN_API: install_reference(settings=None,options=['boost/*:shared=True', 'boost/*:without_atomic=True', 'boost/*:without_chrono=True', 'boost/*:without_container=True', 'boost/*:without_context=True', 'boost/*:without_contract=True', 'boost/*:without_coroutine=True', 'boost/*:without_date_time=True', 'boost/*:without_exception=True', 'boost/*:without_fiber=True', 'boost/*:without_filesystem=True', 'boost/*:without_graph=True', 'boost/*:without_graph_parallel=True', 'boost/*:without_iostreams=True', 'boost/*:without_json=True', 'boost/*:without_log=True', 'boost/*:without_math=True', 'boost/*:without_mpi=True', 'boost/*:without_nowide=True', 'boost/*:without_program_options=True', 'boost/*:without_python=True', 'boost/*:without_random=True', 'boost/*:without_regex=True', 'boost/*:without_serialization=True', 'boost/*:without_stacktrace=True', 'boost/*:without_locale=True', 'boost/*:without_test=True', 'boost/*:without_thread=True', 'boost/*:without_timer=True', 'boost/*:without_type_erasure=True', 'boost/*:without_wave=True'],env=None,conf=None,profile_names=['/Users/kambala/dev/vcmi/vcmi-dev/CI/conan/ios-arm64'],profile_build=ProfileData(profiles=['default'], settings=None, options=None, env=None, conf=None),remote_name=None,verify=None,manifests=None,manifests_interactive=None,build=['missing'],update=False,generators=None,install_folder=None,lockfile=None,lockfile_out=None,lockfile_node_id=None,is_build_require=False,require_overrides=None) [2022-08-31 12:43:31,178]
DEBUG :profile_loader.py[120]: PROFILE LOAD: /Users/kambala/.conan/profiles/default [2022-08-31 12:43:31,179]
DEBUG :profile_loader.py[120]: PROFILE LOAD: /Users/kambala/dev/vcmi/vcmi-dev/CI/conan/ios-arm64 [2022-08-31 12:43:31,180]
DEBUG :profile_loader.py[120]: PROFILE LOAD: /Users/kambala/.conan/profiles/default [2022-08-31 12:43:31,219]
DEBUG :profile_loader.py[120]: PROFILE LOAD: /Users/kambala/.conan/profiles/default [2022-08-31 12:43:31,219]
Configuration (profile_host):
[settings]
arch=armv8
build_type=Release
compiler=apple-clang
compiler.libcxx=libc++
compiler.version=13
os=iOS
os.sdk=iphoneos
os.version=12.0
[options]
boost:shared=True
boost:without_atomic=True
boost:without_chrono=True
boost:without_container=True
boost:without_context=True
boost:without_contract=True
boost:without_coroutine=True
boost:without_date_time=True
boost:without_exception=True
boost:without_fiber=True
boost:without_filesystem=True
boost:without_graph=True
boost:without_graph_parallel=True
boost:without_iostreams=True
boost:without_json=True
boost:without_locale=True
boost:without_log=True
boost:without_math=True
boost:without_mpi=True
boost:without_nowide=True
boost:without_program_options=True
boost:without_python=True
boost:without_random=True
boost:without_regex=True
boost:without_serialization=True
boost:without_stacktrace=True
boost:without_test=True
boost:without_thread=True
boost:without_timer=True
boost:without_type_erasure=True
boost:without_wave=True
[build_requires]
[env]

Configuration (profile_build):
[settings]
arch=x86_64
arch_build=x86_64
build_type=Release
compiler=apple-clang
compiler.libcxx=libc++
compiler.version=13
os=Macos
os_build=Macos
[options]
[build_requires]
[env]

DEBUG :graph_builder.py[462]: GRAPH: new_node: boost/1.79.0 [2022-08-31 12:43:31,287]
DEBUG :graph_builder.py[69]: GRAPH: Time to load deps 0.04548192024230957 [2022-08-31 12:43:31,304]
DEBUG :rest_client_common.py[160]: REST: ping: https://center.conan.io/v1/ping [2022-08-31 12:43:31,307]
DEBUG :rest_client.py [58]: REST: Cached capabilities for the remote: ['complex_search', 'checksum_deploy', 'revisions', 'matrix_params'] [2022-08-31 12:43:31,544]
DEBUG :rest_client_common.py[188]: REST: get: https://center.conan.io/v2/conans/boost/1.79.0/_/_/revisions/3249d9bd2b863a9489767bf9c8a05b4b/packages/a0140e3ac8b131f534142c12ecc5d870e980238c/latest [2022-08-31 12:43:31,544]
DEBUG :rest_client_common.py[30]: REST ERROR: <class 'conans.errors.NotFoundException'> [2022-08-31 12:43:31,690]
DEBUG :rest_client_common.py[160]: REST: ping: https://vcmi.jfrog.io/artifactory/api/conan/vcmi-conan/v1/ping [2022-08-31 12:43:31,694]
DEBUG :rest_client.py [58]: REST: Cached capabilities for the remote: ['complex_search', 'checksum_deploy', 'revisions', 'matrix_params', 'only_v2'] [2022-08-31 12:43:32,424]
DEBUG :rest_client_common.py[188]: REST: get: https://vcmi.jfrog.io/artifactory/api/conan/vcmi-conan/v2/conans/boost/1.79.0/_/_/revisions/3249d9bd2b863a9489767bf9c8a05b4b/packages/a0140e3ac8b131f534142c12ecc5d870e980238c/latest [2022-08-31 12:43:32,425]
DEBUG :rest_client_common.py[30]: REST ERROR: <class 'conans.errors.NotFoundException'> [2022-08-31 12:43:32,820]
DEBUG :rest_client_common.py[188]: REST: get: https://center.conan.io/v2/conans/boost/1.79.0/_/_/revisions/3249d9bd2b863a9489767bf9c8a05b4b/packages/8b2382a6967d0ff86f7fd2df49fa6dc02aaf6341/latest [2022-08-31 12:43:32,822]
DEBUG :rest_client_common.py[30]: REST ERROR: <class 'conans.errors.NotFoundException'> [2022-08-31 12:43:32,966]
DEBUG :rest_client_common.py[188]: REST: get: https://vcmi.jfrog.io/artifactory/api/conan/vcmi-conan/v2/conans/boost/1.79.0/_/_/revisions/3249d9bd2b863a9489767bf9c8a05b4b/packages/8b2382a6967d0ff86f7fd2df49fa6dc02aaf6341/latest [2022-08-31 12:43:32,970]
DEBUG :rest_client_common.py[30]: REST ERROR: <class 'conans.errors.NotFoundException'> [2022-08-31 12:43:33,286]
DEBUG :graph_builder.py[462]: GRAPH: new_node: b2/4.9.2 [2022-08-31 12:43:33,296]
Installing package: boost/1.79.0
Requirements
    boost/1.79.0 from 'conancenter' - Cache
Packages
    boost/1.79.0:a0140e3ac8b131f534142c12ecc5d870e980238c - Build
Build requirements
    b2/4.9.2 from 'conancenter' - Cache
Build requirements packages
    b2/4.9.2:46f53f156846659bf39ad6675fa0ee8156e859fe - Cache

Cross-build from 'Macos:x86_64' to 'iOS:armv8'
Installing (downloading, building) binaries...
b2/4.9.2: Already installed!
boost/1.79.0: Applying build-requirement: b2/4.9.2
boost/1.79.0: Building your package in /Users/kambala/.conan/data/boost/1.79.0/_/_/build/a0140e3ac8b131f534142c12ecc5d870e980238c
INFO  :installer.py   [133]: GENERATORS: Writing generators [2022-08-31 12:43:33,302]
boost/1.79.0: Generator txt created conanbuildinfo.txt
INFO  :installer.py   [137]: TOOLCHAIN: Writing toolchain [2022-08-31 12:43:33,302]
boost/1.79.0: Aggregating env generators
DEBUG :build.py       [11]: Call conanfile.build() with files in build folder: ['conanbuildinfo.txt'] [2022-08-31 12:43:33,302]
boost/1.79.0: Calling build()
WARN: replace_in_file didn't find pattern '$(>) > $(<)' in '/Users/kambala/.conan/data/boost/1.79.0/_/_/source/source_subfolder/libs/stacktrace/build/Jamfile.v2' file.
WARN: replace_in_file didn't find pattern 'local generic-os = [ set.difference $(all-os) : aix darwin vxworks solaris osf hpux ] ;' in '/Users/kambala/.conan/data/boost/1.79.0/_/_/source/source_subfolder/tools/build/src/tools/gcc.jam' file.
WARN: replace_in_file didn't find pattern 'local no-threading = android beos haiku sgi darwin vxworks ;' in '/Users/kambala/.conan/data/boost/1.79.0/_/_/source/source_subfolder/tools/build/src/tools/gcc.jam' file.
WARN: replace_in_file didn't find pattern '    <conditional>@numa' in '/Users/kambala/.conan/data/boost/1.79.0/_/_/source/source_subfolder/libs/fiber/build/Jamfile.v2' file.
boost/1.79.0: WARN: Patching user-config.jam
INFO  :runners.py     [87]: Calling command: xcrun -sdk iphoneos --find clang++ > "/var/folders/r1/j8pmd4951x7_xm15z96k43j80000gn/T/tmp3vcc2g9y/output" [2022-08-31 12:43:33,310]
INFO  :runners.py     [90]: Return code: 0 [2022-08-31 12:43:33,323]
INFO  :runners.py     [98]: Output: in file:/Applications/Xcode13.4.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++
                            
                            stdout: None
                            stderr:b'' [2022-08-31 12:43:33,323]
INFO  :runners.py     [87]: Calling command: xcrun -sdk iphoneos --show-sdk-path > "/var/folders/r1/j8pmd4951x7_xm15z96k43j80000gn/T/tmpf3x8q_9x/output" [2022-08-31 12:43:33,324]
INFO  :runners.py     [90]: Return code: 0 [2022-08-31 12:43:33,333]
INFO  :runners.py     [98]: Output: in file:/Applications/Xcode13.4.1.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS15.5.sdk
                            
                            stdout: None
                            stderr:b'' [2022-08-31 12:43:33,334]
INFO  :runners.py     [87]: Calling command: xcrun -sdk iphoneos --find ar > "/var/folders/r1/j8pmd4951x7_xm15z96k43j80000gn/T/tmpw4tlzj1z/output" [2022-08-31 12:43:33,335]
INFO  :runners.py     [90]: Return code: 0 [2022-08-31 12:43:33,345]
INFO  :runners.py     [98]: Output: in file:/Applications/Xcode13.4.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ar
                            
                            stdout: None
                            stderr:b'' [2022-08-31 12:43:33,346]
INFO  :runners.py     [87]: Calling command: xcrun -sdk iphoneos --find ar > "/var/folders/r1/j8pmd4951x7_xm15z96k43j80000gn/T/tmpst0goe2y/output" [2022-08-31 12:43:33,346]
INFO  :runners.py     [90]: Return code: 0 [2022-08-31 12:43:33,355]
INFO  :runners.py     [98]: Output: in file:/Applications/Xcode13.4.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ar
                            
                            stdout: None
                            stderr:b'' [2022-08-31 12:43:33,356]
INFO  :runners.py     [87]: Calling command: xcrun -sdk iphoneos --find ranlib > "/var/folders/r1/j8pmd4951x7_xm15z96k43j80000gn/T/tmp9ehx8kz1/output" [2022-08-31 12:43:33,356]
INFO  :runners.py     [90]: Return code: 0 [2022-08-31 12:43:33,366]
INFO  :runners.py     [98]: Output: in file:/Applications/Xcode13.4.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ranlib
                            
                            stdout: None
                            stderr:b'' [2022-08-31 12:43:33,366]
INFO  :runners.py     [87]: Calling command: xcrun -sdk iphoneos --find ranlib > "/var/folders/r1/j8pmd4951x7_xm15z96k43j80000gn/T/tmpeywnuw57/output" [2022-08-31 12:43:33,367]
INFO  :runners.py     [90]: Return code: 0 [2022-08-31 12:43:33,376]
INFO  :runners.py     [98]: Output: in file:/Applications/Xcode13.4.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ranlib
                            
                            stdout: None
                            stderr:b'' [2022-08-31 12:43:33,377]
boost/1.79.0: WARN: 
using "clang-darwin" :  :  /Applications/Xcode13.4.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -isysroot /Applications/Xcode13.4.1.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS15.5.sdk -arch arm64 : 
<archiver>"/Applications/Xcode13.4.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ar" <ranlib>"/Applications/Xcode13.4.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ranlib"  ;
boost/1.79.0: Cross building, detecting compiler...
boost/1.79.0: Cross building flags: []
boost/1.79.0: WARN: b2 -q target-os=iphone architecture=arm address-model=64 binary-format=mach-o abi=aapcs --layout=system --user-config=/Users/kambala/.conan/data/boost/1.79.0/_/_/source/source_subfolder/tools/build/user-config.jam -sNO_ZLIB=1 -sNO_BZIP2=1 -sNO_LZMA=1 -sNO_ZSTD=1 boost.locale.icu=off --disable-icu boost.locale.iconv=off --disable-iconv threading=multi visibility=hidden link=shared variant=release --with-system toolset=clang-darwin pch=on linkflags="-stdlib=libc++" cxxflags="-fPIC -stdlib=libc++ -mios-version-min=12.0 -DBOOST_AC_USE_PTHREADS -DBOOST_SP_USE_PTHREADS -fembed-bitcode" install --prefix=/Users/kambala/.conan/data/boost/1.79.0/_/_/package/a0140e3ac8b131f534142c12ecc5d870e980238c -j6 --abbreviate-paths -d0 --debug-configuration --build-dir="/Users/kambala/.conan/data/boost/1.79.0/_/_/build/a0140e3ac8b131f534142c12ecc5d870e980238c"

----Running------
> DYLD_LIBRARY_PATH="" DYLD_FRAMEWORK_PATH="" b2 -q target-os=iphone architecture=arm address-model=64 binary-format=mach-o abi=aapcs --layout=system --user-config=/Users/kambala/.conan/data/boost/1.79.0/_/_/source/source_subfolder/tools/build/user-config.jam -sNO_ZLIB=1 -sNO_BZIP2=1 -sNO_LZMA=1 -sNO_ZSTD=1 boost.locale.icu=off --disable-icu boost.locale.iconv=off --disable-iconv threading=multi visibility=hidden link=shared variant=release --with-system toolset=clang-darwin pch=on linkflags="-stdlib=libc++" cxxflags="-fPIC -stdlib=libc++ -mios-version-min=12.0 -DBOOST_AC_USE_PTHREADS -DBOOST_SP_USE_PTHREADS -fembed-bitcode" install --prefix=/Users/kambala/.conan/data/boost/1.79.0/_/_/package/a0140e3ac8b131f534142c12ecc5d870e980238c -j6 --abbreviate-paths -d0 --debug-configuration --build-dir="/Users/kambala/.conan/data/boost/1.79.0/_/_/build/a0140e3ac8b131f534142c12ecc5d870e980238c"
-----------------
notice: found boost-build.jam at /Users/kambala/.conan/data/boost/1.79.0/_/_/source/source_subfolder/boost-build.jam
notice: loading B2 from /Users/kambala/.conan/data/b2/4.9.2/_/_/package/46f53f156846659bf39ad6675fa0ee8156e859fe/bin/.b2/kernel/bootstrap.jam
notice: Searching '/etc' '/Users/kambala' '/Users/kambala/.conan/data/b2/4.9.2/_/_/package/46f53f156846659bf39ad6675fa0ee8156e859fe/bin/.b2/kernel' '/Users/kambala/.conan/data/b2/4.9.2/_/_/package/46f53f156846659bf39ad6675fa0ee8156e859fe/bin/.b2/util' '/Users/kambala/.conan/data/b2/4.9.2/_/_/package/46f53f156846659bf39ad6675fa0ee8156e859fe/bin/.b2/build' '/Users/kambala/.conan/data/b2/4.9.2/_/_/package/46f53f156846659bf39ad6675fa0ee8156e859fe/bin/.b2/tools' '/Users/kambala/.conan/data/b2/4.9.2/_/_/package/46f53f156846659bf39ad6675fa0ee8156e859fe/bin/.b2/contrib' '/Users/kambala/.conan/data/b2/4.9.2/_/_/package/46f53f156846659bf39ad6675fa0ee8156e859fe/bin/.b2/.' for site-config configuration file 'site-config.jam'.
notice: Configuration file 'site-config.jam' not found in '/etc' '/Users/kambala' '/Users/kambala/.conan/data/b2/4.9.2/_/_/package/46f53f156846659bf39ad6675fa0ee8156e859fe/bin/.b2/kernel' '/Users/kambala/.conan/data/b2/4.9.2/_/_/package/46f53f156846659bf39ad6675fa0ee8156e859fe/bin/.b2/util' '/Users/kambala/.conan/data/b2/4.9.2/_/_/package/46f53f156846659bf39ad6675fa0ee8156e859fe/bin/.b2/build' '/Users/kambala/.conan/data/b2/4.9.2/_/_/package/46f53f156846659bf39ad6675fa0ee8156e859fe/bin/.b2/tools' '/Users/kambala/.conan/data/b2/4.9.2/_/_/package/46f53f156846659bf39ad6675fa0ee8156e859fe/bin/.b2/contrib' '/Users/kambala/.conan/data/b2/4.9.2/_/_/package/46f53f156846659bf39ad6675fa0ee8156e859fe/bin/.b2/.'.
notice: Loading explicitly specified user configuration file:
    /Users/kambala/.conan/data/boost/1.79.0/_/_/source/source_subfolder/tools/build/user-config.jam
notice: Searching '/Users/kambala/.conan/data/boost/1.79.0/_/_/source/source_subfolder/tools/build' for user-config configuration file 'user-config.jam'.
notice: Loading user-config configuration file 'user-config.jam' from '/Users/kambala/.conan/data/boost/1.79.0/_/_/source/source_subfolder/tools/build'.
notice: will use '/Applications/Xcode13.4.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++' '-isysroot' '/Applications/Xcode13.4.1.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS15.5.sdk' '-arch' 'arm64' for clang-darwin, condition <toolset>clang-13
notice: iostreams: not using zlib compression 
notice: iostreams: not using bzip compression 
notice: iostreams: not using lzma compression 
notice: iostreams: not using zstd compression 
notice: [python-cfg] Configuring python...
notice: [python-cfg] Checking interpreter command "python"...
notice: [python-cfg] running command 'python -c "from sys import *; print('version=%d.%d\nplatform=%s\nprefix=%s\nexec_prefix=%s\nexecutable=%s' % (version_info[0],version_info[1],platform,prefix,exec_prefix,executable))" 2>&1'
notice: [python-cfg] ...does not invoke a working interpreter
notice: [python-cfg] Python headers and libraries not found.
Performing configuration checks

    - default address-model    : 64-bit [1]
    - default architecture     : arm [1]

[1] clng-13/trgt-os-iphn

Component configuration:

    - atomic                   : not building
    - chrono                   : not building
    - container                : not building
    - context                  : not building
    - contract                 : not building
    - coroutine                : not building
    - date_time                : not building
    - exception                : not building
    - fiber                    : not building
    - filesystem               : not building
    - graph                    : not building
    - graph_parallel           : not building
    - headers                  : not building
    - iostreams                : not building
    - json                     : not building
    - locale                   : not building
    - log                      : not building
    - math                     : not building
    - mpi                      : not building
    - nowide                   : not building
    - program_options          : not building
    - python                   : not building
    - random                   : not building
    - regex                    : not building
    - serialization            : not building
    - stacktrace               : not building
    - system                   : building
    - test                     : not building
    - thread                   : not building
    - timer                    : not building
    - type_erasure             : not building
    - wave                     : not building

boost/1.79.0: Package 'a0140e3ac8b131f534142c12ecc5d870e980238c' built
boost/1.79.0: Build folder /Users/kambala/.conan/data/boost/1.79.0/_/_/build/a0140e3ac8b131f534142c12ecc5d870e980238c
boost/1.79.0: Generated conaninfo.txt
boost/1.79.0: Generated conanbuildinfo.txt
boost/1.79.0: Generating the package
boost/1.79.0: Package folder /Users/kambala/.conan/data/boost/1.79.0/_/_/package/a0140e3ac8b131f534142c12ecc5d870e980238c
boost/1.79.0: Calling package()
DEBUG :package.py     [73]: PACKAGE: Creating config files to /Users/kambala/.conan/data/boost/1.79.0/_/_/package/a0140e3ac8b131f534142c12ecc5d870e980238c [2022-08-31 12:44:22,658]
boost/1.79.0 package(): Packaged 1 '.txt' file: LICENSE_1_0.txt
boost/1.79.0 package(): Packaged 14658 '.hpp' files
boost/1.79.0 package(): Packaged 148 '.h' files
boost/1.79.0 package(): Packaged 17 files
boost/1.79.0 package(): Packaged 263 '.ipp' files
boost/1.79.0 package(): Packaged 2 '.inc' files: strict_cpp_re.inc, cpp_re.inc
boost/1.79.0 package(): Packaged 1 '.0' file: libboost_system.so.1.79.0
boost/1.79.0 package(): Packaged 1 '.so' file: libboost_system.so
boost/1.79.0: Package 'a0140e3ac8b131f534142c12ecc5d870e980238c' created
boost/1.79.0: Created package revision c617dd10f4130467e15b41f932f50368
Aggregating env generators
```

</details>

The produced .so files are proper .dylibs though:

```
> file /Users/kambala/.conan/data/boost/1.79.0/_/_/package/a0140e3ac8b131f534142c12ecc5d870e980238c/lib/libboost_system.so.1.79.0 
.../libboost_system.so.1.79.0: Mach-O 64-bit dynamically linked shared library arm64

> vtool -show-build /Users/kambala/.conan/data/boost/1.79.0/_/_/package/a0140e3ac8b131f534142c12ecc5d870e980238c/lib/libboost_system.so.1.79.0 
.../libboost_system.so.1.79.0:
Load command 8
      cmd LC_BUILD_VERSION
  cmdsize 32
 platform IOS
    minos 15.5
      sdk 15.5
   ntools 1
     tool LD
  version 764.0
```

For example, in [this Boost build script for iOS](https://github.com/kambala-decapitator/Apple-Boost-BuildScript/blob/build-shared/boost.sh) .dylibs are produced with `link=shared`.


Discussion:

Resolving patch:
diff --git a/recipes/boost/all/conanfile.py b/recipes/boost/all/conanfile.py
--- a/recipes/boost/all/conanfile.py
+++ b/recipes/boost/all/conanfile.py
@@ -253,6 +253,10 @@ def _python_executable(self):
     def _is_windows_platform(self):
         return self.settings.os in ["Windows", "WindowsStore", "WindowsCE"]
 
+    @property
+    def _is_apple_embedded_platform(self):
+        return self.settings.os in ["iOS", "watchOS", "tvOS"]
+
     def config_options(self):
         if self.settings.os == "Windows":
             del self.options.fPIC
@@ -359,7 +363,7 @@ def _shared(self):
 
     @property
     def _stacktrace_addr2line_available(self):
-        if (self.settings.os in ["iOS", "watchOS", "tvOS"] or self.settings.get_safe("os.subsystem") == "catalyst"):
+        if (self._is_apple_embedded_platform or self.settings.get_safe("os.subsystem") == "catalyst"):
              # sandboxed environment - cannot launch external processes (like addr2line), system() function is forbidden
             return False
         return not self.options.header_only and not self.options.without_stacktrace and self.settings.os != "Windows"
@@ -969,7 +973,7 @@ def _build_flags(self):
             flags.append("numa=on")
 
         # https://www.boost.org/doc/libs/1_70_0/libs/context/doc/html/context/architectures.html
-        if self._b2_os:
+        if not self._is_apple_embedded_platform and self._b2_os:
             flags.append(f"target-os={self._b2_os}")
         if self._b2_architecture:
             flags.append(f"architecture={self._b2_architecture}")
@@ -1277,6 +1281,9 @@ def create_library_config(deps_name, name):
         if asflags.strip():
             contents += f'<asmflags>"{asflags.strip()}" '
 
+        if self._is_apple_embedded_platform:
+            contents += f'<target-os>"{self._b2_os}" '
+
         contents += " ;"
 
         self.output.warn(contents)


Test patch: