安装 r 里的 igraph 报错: 

foreign-graphml.c: In function ‘igraph_write_graph_graphml’:
foreign-graphml.c:1408:46: error: expected ‘)’ before ‘GRAPHML_NAMESPACE_URI’
   ret=fprintf(outstream, "<graphml xmlns=\"" GRAPHML_NAMESPACE_URI "\"\n");
                                              ^
foreign-graphml.c:1412:59: error: expected ‘)’ before ‘GRAPHML_NAMESPACE_URI’
   ret=fprintf(outstream, "         xsi:schemaLocation=\"" GRAPHML_NAMESPACE_URI "\n");
                                                           ^
foreign-graphml.c:1414:38: error: expected ‘)’ before ‘GRAPHML_NAMESPACE_URI’
   ret=fprintf(outstream, "         " GRAPHML_NAMESPACE_URI "/1.0/graphml.xsd\">\n");
                                      ^
/home/genek/miniconda3/lib/R/etc/Makeconf:133: recipe for target ‘foreign-graphml.o‘ failed
make: *** [foreign-graphml.o] Error 1
ERROR: compilation failed for package ‘igraph’
* removing ‘/home/genek/miniconda3/lib/R/library/igraph’
* restoring previous ‘/home/genek/miniconda3/lib/R/library/igraph’

解决办法

sudo apt-get install libxml2-dev