# Trying to understand why PCF8574 model is trying to compile old version of epoll?

**URL:** <https://discourse.nodered.org/t/trying-to-understand-why-pcf8574-model-is-trying-to-compile-old-version-of-epoll/30794>\
**Category:** General\
**Created:** [27 July 2020 20:51 UTC](https://discourse.nodered.org/t/trying-to-understand-why-pcf8574-model-is-trying-to-compile-old-version-of-epoll/30794 "2020-07-27T20:51:18Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Nodi.Rubrum](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/nodi.rubrum/32/107482_2.png) [@Nodi.Rubrum](https://discourse.nodered.org/u/Nodi.Rubrum)\
**Post date:** [27 July 2020 20:51 UTC](https://discourse.nodered.org/t/trying-to-understand-why-pcf8574-model-is-trying-to-compile-old-version-of-epoll/30794/1 "2020-07-27T20:51:18Z")

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I am trying to load the PCF8574 module for NR. It is ancient so not surprised I am running into issues. But one specific issue, has me... confused I guess.

I explicitly loaded the latest version of the dependencies for PCF8574, per the package,json. These load fine into npm of course. I then try to load PCF8574... thinking I might get it to load but fail at some point. But the install is trying ot compile a very old version of epoll. But epoll is not referenced as a dependency that I can find.  
For example...

```auto
make: Entering directory '/home/pi/.node-red/node_modules/pcf8574/node_modules/epoll/build'

```

Since the install of PCF8574 module fails, I can't find it under .node-red/pcf8574 directory. Is there a staging area for installs, other than node\_modules directory?

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**Author:** ![Steve-Mcl](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/steve-mcl/32/4826_2.png) [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)\
**Post date:** [27 July 2020 20:58 UTC](https://discourse.nodered.org/t/trying-to-understand-why-pcf8574-model-is-trying-to-compile-old-version-of-epoll/30794/2 "2020-07-27T20:58:35Z")

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If it is [this](https://www.npmjs.com/package/pcf8574) lib then it has a dependency to an old version of `onoff` which has a dependency on an old version of `epoll`

This lib is 3y of and possibly abandoned.

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**Author:** ![Nodi.Rubrum](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/nodi.rubrum/32/107482_2.png) [@Nodi.Rubrum](https://discourse.nodered.org/u/Nodi.Rubrum)\
**Post date:** [28 July 2020 02:44 UTC](https://discourse.nodered.org/t/trying-to-understand-why-pcf8574-model-is-trying-to-compile-old-version-of-epoll/30794/3 "2020-07-28T02:44:58Z")

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Yup, I gave up as it got more twisted, the more I tried solve the issue. Does not appear there are any current/recent node modules for the simple PCF8574 GPIO expansion boards? I use a few of these to drive multiple relay boards, ganged Mosfets, etc.

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**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [26 September 2020 02:45 UTC](https://discourse.nodered.org/t/trying-to-understand-why-pcf8574-model-is-trying-to-compile-old-version-of-epoll/30794/4 "2020-09-26T02:45:03Z")

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Closed on 26 September 2020 02:45 UTC

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