Chad: They are as far as I know. 

Mithuaru:

 5808 configure:17366: checking for libxml-2.0 > 2.6.17
 5809 configure:17373: $PKG_CONFIG --exists --print-errors "libxml-2.0 > 2.6.17"
 5810 configure:17376: $? = 0
 5811 configure:17390: $PKG_CONFIG --exists --print-errors "libxml-2.0 > 2.6.17"
 5812 configure:17393: $? = 0
 5813 configure:17431: result: yes
 5814 configure:17466: checking for htmlReadMemory in -lxml2
 5815 configure:17491: gcc -o conftest -g3 -O2     conftest.c -lxml2 -lxml2   >&5
 5816 configure:17491: $? = 0
 5817 configure:17500: result: yes
 5818 configure:17529: checking for maillock in -lmail

Thank you 

- Zach 

On 27 Sep 2019, at 18:22, chad <yandros@gmail.com> wrote:

Files in /usr/local/Cellar are generally placed there/managed by homebrew, aren't they? 

On Wed, Sep 25, 2019 at 4:08 PM Zach Pearson <zach@zjp.codes> wrote:
No. I the first directory, the headers are one folder deeper in a directory fully called

/usr/local/Cellar/libxml2/2.9.9_2/include/libxml2/libxml

In the second, the libraries are present.

> On 25 Sep 2019, at 17:47, mituharu@math.s.chiba-u.ac.jp wrote:
>
>> To the first:
>>
>> -I/usr/local/Cellar/libxml2/2.9.9_2/include/libxml2
>> -L/usr/local/Cellar/libxml2/2.9.9_2/lib -lxml2
>>
>> And the second:
>>
>> /usr/local/opt/libxml2/lib/pkgconfig
>
> Do you have header files and libraries in the directories
> shown in the first output?
>
>                                       YAMAMOTO Mitsuharu
>                               mituharu@math.s.chiba-u.ac.jp
>
>
>