Workaround for #156.

script/ci_build.sh

 apt-get install -y python3-pip
 pip3 install conan
 
+# #156 Workaround for conan#4938
+mkdir -p ~/.conan
+cp script/settings.yml ~/.conan/
+
 
 if [[ "${CXX}" == clang* ]]
 then

script/settings.yml

+# Only for cross building, 'os_build/arch_build' is the system that runs Conan
+os_build: [Windows, WindowsStore, Linux, Macos, FreeBSD, SunOS]
+arch_build: [x86, x86_64, ppc32, ppc64le, ppc64, armv5el, armv5hf, armv6, armv7, armv7hf, armv7s, armv7k, armv8, armv8_32, armv8.3, sparc, sparcv9, mips, mips64, avr, s390, s390x]
+
+# Only for building cross compilation tools, 'os_target/arch_target' is the system for
+# which the tools generate code
+os_target: [Windows, Linux, Macos, Android, iOS, watchOS, tvOS, FreeBSD, SunOS, Arduino]
+arch_target: [x86, x86_64, ppc32, ppc64le, ppc64, armv5el, armv5hf, armv6, armv7, armv7hf, armv7s, armv7k, armv8, armv8_32, armv8.3, sparc, sparcv9, mips, mips64, avr, s390, s390x, asm.js, wasm]
+
+# Rest of the settings are "host" settings:
+# - For native building/cross building: Where the library/program will run.
+# - For building cross compilation tools: Where the cross compiler will run.
+os:
+    Windows:
+        subsystem: [None, cygwin, msys, msys2, wsl]
+    WindowsStore:
+        version: ["8.1", "10.0"]
+    WindowsCE:
+        platform: ANY
+        version: ["5.0", "6.0", "7.0", "8.0"]
+    Linux:
+    Macos:
+        version: [None, "10.6", "10.7", "10.8", "10.9", "10.10", "10.11", "10.12", "10.13", "10.14"]
+    Android:
+        api_level: ANY
+    iOS:
+        version: ["7.0", "7.1", "8.0", "8.1", "8.2", "8.3", "9.0", "9.1", "9.2", "9.3", "10.0", "10.1", "10.2", "10.3", "11.0", "11.1", "11.2", "11.3", "11.4", "12.0", "12.1"]
+    watchOS:
+        version: ["4.0", "4.1", "4.2", "4.3", "5.0", "5.1"]
+    tvOS:
+        version: ["11.0", "11.1", "11.2", "11.3", "11.4", "12.0", "12.1"]
+    FreeBSD:
+    SunOS:
+    Arduino:
+        board: ANY
+    Emscripten:
+arch: [x86, x86_64, ppc32, ppc64le, ppc64, armv4, armv4i, armv5el, armv5hf, armv6, armv7, armv7hf, armv7s, armv7k, armv8, armv8_32, armv8.3, sparc, sparcv9, mips, mips64, avr, s390, s390x, asm.js, wasm]
+compiler:
+    sun-cc:
+        version: ["5.10", "5.11", "5.12", "5.13", "5.14"]
+        threads: [None, posix]
+        libcxx: [libCstd, libstdcxx, libstlport, libstdc++]
+    gcc:
+        version: ["4.1", "4.4", "4.5", "4.6", "4.7", "4.8", "4.9",
+                  "5", "5.1", "5.2", "5.3", "5.4", "5.5",
+                  "6", "6.1", "6.2", "6.3", "6.4",
+                  "7", "7.1", "7.2", "7.3",
+                  "8", "8.1", "8.2",
+                  "9"]
+        libcxx: [libstdc++, libstdc++11]
+        threads: [None, posix, win32] #  Windows MinGW
+        exception: [None, dwarf2, sjlj, seh] # Windows MinGW
+        cppstd: [None, 98, gnu98, 11, gnu11, 14, gnu14, 17, gnu17, 20, gnu20]
+    Visual Studio:
+        runtime: [MD, MT, MTd, MDd]
+        version: ["8", "9", "10", "11", "12", "14", "15", "16"]
+        toolset: [None, v90, v100, v110, v110_xp, v120, v120_xp,
+                  v140, v140_xp, v140_clang_c2, LLVM-vs2012, LLVM-vs2012_xp,
+                  LLVM-vs2013, LLVM-vs2013_xp, LLVM-vs2014, LLVM-vs2014_xp,
+                  LLVM-vs2017, LLVM-vs2017_xp, v141, v141_xp, v141_clang_c2, v142]
+        cppstd: [None, 14, 17, 20]
+    clang:
+        version: ["3.3", "3.4", "3.5", "3.6", "3.7", "3.8", "3.9", "4.0",
+                  "5.0", "6.0", "7.0", "7.1",
+                  "8"]
+        libcxx: [libstdc++, libstdc++11, libc++]
+        cppstd: [None, 98, gnu98, 11, gnu11, 14, gnu14, 17, gnu17, 20, gnu20]
+    apple-clang:
+        version: ["5.0", "5.1", "6.0", "6.1", "7.0", "7.3", "8.0", "8.1", "9.0", "9.1", "10.0"]
+        libcxx: [libstdc++, libc++]
+        cppstd: [None, 98, gnu98, 11, gnu11, 14, gnu14, 17, gnu17, 20, gnu20]
+
+build_type: [None, Debug, Release, RelWithDebInfo, MinSizeRel]
+cppstd: [None, 98, gnu98, 11, gnu11, 14, gnu14, 17, gnu17, 20, gnu20]  # Deprecated, use compiler.cppstd