GemパッケージをインストールするときにC++11を指定する
2019-12-29
bitcoinrb を mac で使うために leveldb-native を gem install しようとしたら，ビルドに失敗しました．どうやらオプションの指定が必要なようです．
エラー内容
原因は std=c++11 をオプションに指定していないことのようです．
エラー文の詳細は以下の通りです．
terminal
$ gem i leveldb-native
Building native extensions. This could take a while...
ERROR: Error installing leveldb-native:
ERROR: Failed to build gem native extension.
current directory: /Users/mktia/.rbenv/versions/2.6.3/lib/ruby/gems/2.6.0/gems/leveldb-native-0.6/ext/leveldb-native
/Users/mktia/.rbenv/versions/2.6.3/bin/ruby -I /Users/mktia/.rbenv/versions/2.6.3/lib/ruby/2.6.0 -r ./siteconf20191226-1456-1crdg7e.rb extconf.rb
checking for -lleveldb... yes
creating Makefile
current directory: /Users/mktia/.rbenv/versions/2.6.3/lib/ruby/gems/2.6.0/gems/leveldb-native-0.6/ext/leveldb-native
make "DESTDIR=" clean
current directory: /Users/mktia/.rbenv/versions/2.6.3/lib/ruby/gems/2.6.0/gems/leveldb-native-0.6/ext/leveldb-native
make "DESTDIR="
compiling leveldb-native.cc
In file included from leveldb-native.cc:4:
In file included from /usr/local/include/leveldb/db.h:12:
In file included from /usr/local/include/leveldb/iterator.h:20:
/usr/local/include/leveldb/status.h:27:11: error: expected ';' at end of declaration list
Status() noexcept : state_(nullptr) {}
^
/usr/local/include/leveldb/status.h:33:23: error: expected ';' at end of declaration list
Status(Status&& rhs) noexcept : state_(rhs.state_) { rhs.state_ = nullptr; }
^
/usr/local/include/leveldb/status.h:103:16: error: 'Status' is missing exception specification 'throw()'
inline Status::Status(const Status& rhs) {
^
/usr/local/include/leveldb/status.h:24:22: note: previous declaration is here
class LEVELDB_EXPORT Status {
^
/usr/local/include/leveldb/status.h:115:48: error: expected function body after function declarator
inline Status& Status::operator=(Status&& rhs) noexcept {
^
4 errors generated.
make: *** [leveldb-native.o] Error 1
make failed, exit code 2
C++コンパイラをオプションで指定する
terminal
$ gem help install
Usage: gem install GEMNAME [GEMNAME ...] [options] -- --build-flags [options]
Options:
--platform PLATFORM Specify the platform of gem to install
-v, --version VERSION Specify version of gem to install
--[no-]prerelease Allow prerelease versions of a gem
to be installed. (Only for listed gems)
...
--build-flags のところで設定すればうまくいきそうです．
$ gem i leveldb-native -- --with-cxxflags=-std=c++11
Building native extensions with: '--with-cxxflags=-std=c++11'
This could take a while...
Successfully installed leveldb-native-0.6
Parsing documentation for leveldb-native-0.6
Done installing documentation for leveldb-native after 0 seconds
1 gem installed
終わり