Merge #6109: fix: fix depends builds on FreeBSD hosts

bbc9957 fix: sidestep c++17 std::unary_function removal by compiling boost with c++11 (Kittywhiskers Van Gogh)
3c622a3 revert: partial dash#5610 (make depends compilable with Xcode 15 on macos) (Kittywhiskers Van Gogh)
f15e1db fix: make `std::unary_function` suppression flag no longer contingent on `--enable-suppress-external-warnings` (Kittywhiskers Van Gogh)
5db84e2 revert: partial dash#3003 (Fix 2 common Travis failures which happen when Travis has network issues) (Kittywhiskers Van Gogh)

Pull request description:

  ## Additional Information

  Despite builders for BSD-based platforms being backported as early as [dash#5362](#5362), they didn't work on account of using a `curl` flag, `--retry`, that was lopped off other builders in [dash#3003](#3003) as a way to mitigate aberrant Travis CI-specific behaviour.

  As the variable `$(DOWNLOAD_RETRIES)` was removed as part of that mitigation, the introduction of builders that rely on this variable caused failures as the flag was accompanied by nothing. As our CI host isn't based on FreeBSD, this went unnoticed. When deciding between extending the existing patch and reverting it, reverting it proved to be more attractive on account of us no longer using Travis CI and the revert bringing us closer to upstream.

  Additionally, the `std::unary_function` patch that was introduced in [dash#5610](#5610) proves to be necessary on BSD-based platforms as well (had to be extended for and tested on GhostBSD, based on FreeBSD 13.2-STABLE, Clang 16). Instead of conditionally patching based on platform and compiler, a more reliable patch would be to downgrade the C++ version used to build Boost at the last version to have `std::unary_function`, which would be C++11, albeit deprecated ([source](https://en.cppreference.com/w/cpp/utility/functional/unary_function)).

  Though it's likely this route wasn't taken originally due to compiler errors that happened despite downgrading to C++11. These errors were due to the compiler objecting to `std::unary_function` usage in Boost headers, despite the backport of [bitcoin#25436](bitcoin#25436), which should've solved this problem. The reason the errors were still persisting is because the necessary flag, `-DBOOST_NO_CXX98_FUNCTION_BASE`, was only applied if `--enable-suppress-external-warnings` was set. CI didn't catch this, as the flag is always set, to keep log lengths manageable. This has been rectified.

  All changes combined, one should be able to build non-Qt Dash binaries using `depends` though building the Qt client from `depends`  unfortunately remains a problem, even upstream ([source](bitcoin#23955 (comment)), [source](bitcoin#23948 (comment))).

  ## Demo

  **Based on bbc9957**

  Built using:
  * **`depends` flags:** `NO_QT=1 ALLOW_HOST_PACKAGES=1 HOST=x86_64-unknown-freebsd13.2`
  * **`configure` flags :** `--prefix=$(pwd)/depends/x86_64-unknown-freebsd13.2 --enable-debug --enable-suppress-external-warnings --with-gui`
  * Qt installed using `pkg` (`qt5`)

  ![Dash-Qt running on GhostBSD](https://github.com/dashpay/dash/assets/63189531/608ff7e6-0e53-41a6-92dd-e31ab2c76e2e)

  ## Checklist:

  - [x] I have performed a self-review of my own code **(note: N/A)**
  - [x] I have commented my code, particularly in hard-to-understand areas **(note: N/A)**
  - [x] I have added or updated relevant unit/integration/functional/e2e tests **(note: N/A)**
  - [x] I have made corresponding changes to the documentation **(note: N/A)**
  - [x] I have assigned this pull request to a milestone _(for repository code-owners and collaborators only)_

ACKs for top commit:
  UdjinM6:
    light ACK bbc9957
  PastaPastaPasta:
    utACK bbc9957
  knst:
    ACK bbc9957

Tree-SHA512: b29d6775f42965d2f09307aff0192012aa192e39e06a83b800613831dc00fc7173201d496117fbe86850f5208a0b7688a376f2ee618881c062c28d694085efc9

Author: PastaPastaPasta

configure.ac

@@ -1458,6 +1458,12 @@ AX_BOOST_BASE([1.64.0],[],[AC_MSG_ERROR([Boost is not available!])])
 if test x$want_boost = xno; then
     AC_MSG_ERROR([[only libdashconsensus can be built without boost]])
 fi
+
+dnl Prevent use of std::unary_function, which was removed in C++17,
+dnl and will generate warnings with newer compilers.
+dnl See: https://github.com/boostorg/container_hash/issues/22.
+BOOST_CPPFLAGS="$BOOST_CPPFLAGS -DBOOST_NO_CXX98_FUNCTION_BASE"
+
 AX_BOOST_FILESYSTEM
 
 dnl Opt-in to Boost Process
@@ -1471,11 +1477,6 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <boost/process.hpp>]],
 fi
 
 if test x$suppress_external_warnings != xno; then
-    dnl Prevent use of std::unary_function, which was removed in C++17,
-    dnl and will generate warnings with newer compilers.
-    dnl See: https://github.com/boostorg/container_hash/issues/22.
-    BOOST_CPPFLAGS="$BOOST_CPPFLAGS -DBOOST_NO_CXX98_FUNCTION_BASE"
-
     BOOST_CPPFLAGS=SUPPRESS_WARNINGS($BOOST_CPPFLAGS)
 fi
 

depends/Makefile

@@ -49,6 +49,7 @@ PATCHES_PATH = $(BASEDIR)/patches
 BASEDIR = $(CURDIR)
 HASH_LENGTH:=11
 DOWNLOAD_CONNECT_TIMEOUT:=30
+DOWNLOAD_RETRIES:=3
 HOST_ID_SALT ?= salt
 BUILD_ID_SALT ?= salt
 

depends/builders/darwin.mk

@@ -7,7 +7,7 @@ build_darwin_OTOOL:=$(shell xcrun -f otool)
 build_darwin_NM:=$(shell xcrun -f nm)
 build_darwin_INSTALL_NAME_TOOL:=$(shell xcrun -f install_name_tool)
 build_darwin_SHA256SUM=shasum -a 256
-build_darwin_DOWNLOAD=curl --location --fail --connect-timeout $(DOWNLOAD_CONNECT_TIMEOUT) -o
+build_darwin_DOWNLOAD=curl --location --fail --connect-timeout $(DOWNLOAD_CONNECT_TIMEOUT) --retry $(DOWNLOAD_RETRIES) -o
 
 #darwin host on darwin builder. overrides darwin host preferences.
 darwin_CC=$(shell xcrun -f clang) -mmacosx-version-min=$(OSX_MIN_VERSION) -isysroot$(shell xcrun --show-sdk-path)

depends/builders/linux.mk

@@ -1,2 +1,2 @@
 build_linux_SHA256SUM = sha256sum
-build_linux_DOWNLOAD = curl --location --fail --connect-timeout $(DOWNLOAD_CONNECT_TIMEOUT) -o
+build_linux_DOWNLOAD = curl --location --fail --connect-timeout $(DOWNLOAD_CONNECT_TIMEOUT) --retry $(DOWNLOAD_RETRIES) -o

depends/funcs.mk

@@ -37,8 +37,6 @@ endef
 define fetch_file
     ( test -f $$($(1)_source_dir)/$(4) || \
     ( $(call fetch_file_inner,$(1),$(2),$(3),$(4),$(5)) || \
-      (sleep 5 && $(call fetch_file_inner,$(1),$(2),$(3),$(4),$(5))) || \
-      (sleep 10 && $(call fetch_file_inner,$(1),$(2),$(3),$(4),$(5))) || \
       $(call fetch_file_inner,$(1),$(FALLBACK_DOWNLOAD_PATH),$(3),$(4),$(5))))
 endef
 

depends/packages/boost.mk

@@ -21,27 +21,21 @@ $(package)_config_opts_i686_android=address-model=32
 $(package)_config_opts_aarch64_android=address-model=64
 $(package)_config_opts_x86_64_android=address-model=64
 $(package)_config_opts_armv7a_android=address-model=32
-unary_function=unary_function
 ifneq (,$(findstring clang,$($(package)_cxx)))
 $(package)_toolset_$(host_os)=clang
-ifeq ($(build_os),darwin)
-unary_function=__unary_function
-endif
 else
 $(package)_toolset_$(host_os)=gcc
 endif
 $(package)_config_libraries=filesystem,test
-$(package)_cxxflags=-std=c++17
+$(package)_cxxflags=-std=c++11
 $(package)_cxxflags_linux=-fPIC
 $(package)_cxxflags_freebsd=-fPIC
 $(package)_cxxflags_openbsd=-fPIC
 $(package)_cxxflags_android=-fPIC
 $(package)_cxxflags_x86_64=-fcf-protection=full
 endef
 
-# Fix missing unary_function in clang15 on macos, can be removed after upgrading to 1.81
 define $(package)_preprocess_cmds
-  sed -i.old "s/unary_function/$(unary_function)/" boost/container_hash/hash.hpp && \
   echo "using $($(package)_toolset_$(host_os)) : : $($(package)_cxx) : <cflags>\"$($(package)_cflags)\" <cxxflags>\"$($(package)_cxxflags)\" <compileflags>\"$($(package)_cppflags)\" <linkflags>\"$($(package)_ldflags)\" <archiver>\"$($(package)_ar)\" <striper>\"$(host_STRIP)\"  <ranlib>\"$(host_RANLIB)\" <rc>\"$(host_WINDRES)\" : ;" > user-config.jam
 endef