Ionic 4 beta takes a long time to compile

Question

I upgraded my app from version beta.7 to version beta.12, and I'm experiencing slow compilation time.

To sum it up, I checked how much time it takes for each version to run ionic serve:

• 4.0.0-beta.7 - 15082ms
• 4.0.0-beta.11 - 21500ms
• 4.0.0-beta.12 - 63857ms

As you can see, version 4.0.0-beta.12 significantly takes more time than its previous versions. Even when it listens for changes, it takes a long time to compile.

The outputs I get from each version:

4.0.0-beta.7 ionic serve:

    [INFO] Browser window opened to http://localhost:8100!

    [ng] i ｢wdm｣: wait until bundle finished: /
    [ng]
    [ng] Date: 2018-09-27T09:21:25.403Z
    [ng] Hash: 4da9f0606c7bea51328f
    [ng] Time: 15082ms
    [ng] chunk {common} common.js, common.js.map (common) 10.6 kB  [rendered]
    [ng] chunk {home-home-module} home-home-module.js, home-home-module.js.map (home-home-module) 5.58 kB  [rendered]
    [ng] chunk {login-login-module} login-login-module.js, login-login-module.js.map (login-login-module) 18 kB  [rendered]
    [ng] chunk {main} main.js, main.js.map (main) 76.4 kB [initial] [rendered]
    [ng] chunk {page-page-module} page-page-module.js, page-page-module.js.map (page-page-module) 39.1 kB  [rendered]
    [ng] chunk {polyfills} polyfills.js, polyfills.js.map (polyfills) 226 kB [initial] [rendered]
    [ng] chunk {register-register-module} register-register-module.js, register-register-module.js.map (register-register-module) 16.1 kB  [rendered]
    [ng] chunk {runtime} runtime.js, runtime.js.map (runtime) 8.16 kB [entry] [rendered]
    [ng] chunk {styles} styles.js, styles.js.map (styles) 36.2 kB [initial] [rendered]
    [ng] chunk {129} 129.js, 129.js.map () 14.9 kB  [rendered]
    [ng] chunk {vendor} vendor.js, vendor.js.map (vendor) 5.86 MB [initial] [rendered]
    [ng] chunk {0} 0.js, 0.js.map () 46 kB  [rendered]
    [ng] chunk {1} 1.js, 1.js.map () 43.5 kB  [rendered]
    [ng] chunk {2} 2.js, 2.js.map () 45.6 kB  [rendered]
    [ng] chunk {3} 3.js, 3.js.map () 43.3 kB  [rendered]
    [ng] chunk {4} 4.js, 4.js.map () 3.25 kB  [rendered]
    [ng] chunk {5} 5.js, 5.js.map () 3.19 kB  [rendered]
    [ng] chunk {6} 6.js, 6.js.map () 210 kB  [rendered]
    [ng] chunk {7} 7.js, 7.js.map () 204 kB  [rendered]
    [ng] chunk {8} 8.js, 8.js.map () 210 kB  [rendered]
    [ng] chunk {9} 9.js, 9.js.map () 204 kB  [rendered]
    ...
    [ng] chunk {128} 128.js, 128.js.map () 7.29 kB  [rendered]
    [ng] i ｢wdm｣: Compiled successfully.

4.0.0-beta.11 ionic serve:

    [INFO] Browser window opened to http://localhost:8100!

    [ng] i ｢wdm｣: wait until bundle finished: /
    [ng]
    [ng] Date: 2018-09-27T09:19:46.327Z
    [ng] Hash: 13cd4e173af941a94389
    [ng] Time: 21500ms
    [ng] chunk {common} common.js, common.js.map (common) 22.9 kB  [rendered]
    [ng] chunk {home-home-module} home-home-module.js, home-home-module.js.map (home-home-module) 5.58 kB  [rendered]
    [ng] chunk {login-login-module} login-login-module.js, login-login-module.js.map (login-login-module) 18 kB  [rendered]
    [ng] chunk {main} main.js, main.js.map (main) 96.5 kB [initial] [rendered]
    [ng] chunk {page-page-module} page-page-module.js, page-page-module.js.map (page-page-module) 39.1 kB  [rendered]
    [ng] chunk {polyfills} polyfills.js, polyfills.js.map (polyfills) 226 kB [initial] [rendered]
    [ng] chunk {register-register-module} register-register-module.js, register-register-module.js.map (register-register-module) 16.1 kB  [rendered]
    [ng] chunk {runtime} runtime.js, runtime.js.map (runtime) 8.16 kB [entry] [rendered]
    [ng] chunk {styles} styles.js, styles.js.map (styles) 36.2 kB [initial] [rendered]
    [ng] chunk {166} 166.js, 166.js.map () 14.6 kB  [rendered]
    [ng] chunk {vendor} vendor.js, vendor.js.map (vendor) 5.76 MB [initial] [rendered]
    [ng] chunk {0} 0.js, 0.js.map () 14.7 kB  [rendered]
    [ng] chunk {1} 1.js, 1.js.map () 1.27 kB  [rendered]
    [ng] chunk {2} 2.js, 2.js.map () 2.36 kB  [rendered]
    [ng] chunk {3} 3.js, 3.js.map () 1.39 kB  [rendered]
    [ng] chunk {4} 4.js, 4.js.map () 8.11 kB  [rendered]
    [ng] chunk {5} 5.js, 5.js.map () 5.14 kB  [rendered]
    [ng] chunk {6} 6.js, 6.js.map () 48 kB  [rendered]
    [ng] chunk {7} 7.js, 7.js.map () 48 kB  [rendered]
    [ng] chunk {8} 8.js, 8.js.map () 22.9 kB  [rendered]
    [ng] chunk {9} 9.js, 9.js.map () 22.9 kB  [rendered]
    [ng] chunk {10} 10.js, 10.js.map () 12.3 kB  [rendered]
    [ng] chunk {11} 11.js, 11.js.map () 12.5 kB  [rendered]
    [ng] chunk {12} 12.js, 12.js.map () 15.9 kB  [rendered]
    [ng] chunk {13} 13.js, 13.js.map () 15.9 kB  [rendered]
    [ng] chunk {14} 14.js, 14.js.map () 17.7 kB  [rendered]
    [ng] chunk {15} 15.js, 15.js.map () 17.7 kB  [rendered]
    [ng] chunk {16} 16.js, 16.js.map () 19.9 kB  [rendered]
    [ng] chunk {17} 17.js, 17.js.map () 19.9 kB  [rendered]
    [ng] chunk {18} 18.js, 18.js.map () 5.11 kB  [rendered]
    [ng] chunk {19} 19.js, 19.js.map () 5.18 kB  [rendered]
    [ng] chunk {20} 20.js, 20.js.map () 34.4 kB  [rendered]
    [ng] chunk {21} 21.js, 21.js.map () 35.7 kB  [rendered]
    [ng] chunk {22} 22.js, 22.js.map () 7.67 kB  [rendered]
    [ng] chunk {23} 23.js, 23.js.map () 7.68 kB  [rendered]
    [ng] chunk {24} 24.js, 24.js.map () 16.1 kB  [rendered]
    [ng] chunk {25} 25.js, 25.js.map () 16.1 kB  [rendered]
    [ng] chunk {26} 26.js, 26.js.map () 4.28 kB  [rendered]
    [ng] chunk {27} 27.js, 27.js.map () 4.33 kB  [rendered]
    [ng] chunk {28} 28.js, 28.js.map () 23.1 kB  [rendered]
    [ng] chunk {29} 29.js, 29.js.map () 23.2 kB  [rendered]
    [ng] chunk {30} 30.js, 30.js.map () 31.1 kB  [rendered]
    [ng] chunk {31} 31.js, 31.js.map () 31.1 kB  [rendered]
    [ng] chunk {32} 32.js, 32.js.map () 11.2 kB  [rendered]
    [ng] chunk {33} 33.js, 33.js.map () 11.2 kB  [rendered]
    [ng] chunk {34} 34.js, 34.js.map () 16.3 kB  [rendered]
    [ng] chunk {35} 35.js, 35.js.map () 16.3 kB  [rendered]
    [ng] chunk {36} 36.js, 36.js.map () 8.81 kB  [rendered]
    [ng] chunk {37} 37.js, 37.js.map () 9.07 kB  [rendered]
    [ng] chunk {38} 38.js, 38.js.map () 57.1 kB  [rendered]
    [ng] chunk {39} 39.js, 39.js.map () 57.5 kB  [rendered]
    [ng] chunk {40} 40.js, 40.js.map () 63.4 kB  [rendered]
    [ng] chunk {41} 41.js, 41.js.map () 63.4 kB  [rendered]
    [ng] chunk {42} 42.js, 42.js.map () 43.1 kB  [rendered]
    [ng] chunk {43} 43.js, 43.js.map () 43.2 kB  [rendered]
    [ng] chunk {44} 44.js, 44.js.map () 11.6 kB  [rendered]
    [ng] chunk {45} 45.js, 45.js.map () 11.8 kB  [rendered]
    [ng] chunk {46} 46.js, 46.js.map () 16.1 kB  [rendered]
    [ng] chunk {47} 47.js, 47.js.map () 16.1 kB  [rendered]
    [ng] chunk {48} 48.js, 48.js.map () 23 kB  [rendered]
    [ng] chunk {49} 49.js, 49.js.map () 23.1 kB  [rendered]
    [ng] chunk {50} 50.js, 50.js.map () 12.1 kB  [rendered]
    [ng] chunk {51} 51.js, 51.js.map () 12.3 kB  [rendered]
    [ng] chunk {52} 52.js, 52.js.map () 16 kB  [rendered]
    [ng] chunk {53} 53.js, 53.js.map () 16.6 kB  [rendered]
    [ng] chunk {54} 54.js, 54.js.map () 10.9 kB  [rendered]
    [ng] chunk {55} 55.js, 55.js.map () 11 kB  [rendered]
    [ng] chunk {56} 56.js, 56.js.map () 34.3 kB  [rendered]
    [ng] chunk {57} 57.js, 57.js.map () 35.6 kB  [rendered]
    [ng] chunk {58} 58.js, 58.js.map () 57.1 kB  [rendered]
    [ng] chunk {59} 59.js, 59.js.map () 57.5 kB  [rendered]
    [ng] chunk {60} 60.js, 60.js.map () 19.5 kB  [rendered]
    [ng] chunk {61} 61.js, 61.js.map () 19.5 kB  [rendered]
    [ng] chunk {62} 62.js, 62.js.map () 13.8 kB  [rendered]
    [ng] chunk {63} 63.js, 63.js.map () 14.2 kB  [rendered]
    [ng] chunk {64} 64.js, 64.js.map () 8.95 kB  [rendered]
    [ng] chunk {65} 65.js, 65.js.map () 9.19 kB  [rendered]
    [ng] chunk {66} 66.js, 66.js.map () 32.4 kB  [rendered]
    [ng] chunk {67} 67.js, 67.js.map () 32.8 kB  [rendered]
    [ng] chunk {68} 68.js, 68.js.map () 23.5 kB  [rendered]
    [ng] chunk {69} 69.js, 69.js.map () 23.5 kB  [rendered]
    [ng] chunk {70} 70.js, 70.js.map () 9.71 kB  [rendered]
    [ng] chunk {71} 71.js, 71.js.map () 10.1 kB  [rendered]
    [ng] chunk {72} 72.js, 72.js.map () 9.97 kB  [rendered]
    [ng] chunk {73} 73.js, 73.js.map () 10 kB  [rendered]
    [ng] chunk {74} 74.js, 74.js.map () 48 kB  [rendered]
    [ng] chunk {75} 75.js, 75.js.map () 48 kB  [rendered]
    [ng] chunk {76} 76.js, 76.js.map () 5.65 kB  [rendered]
    [ng] chunk {77} 77.js, 77.js.map () 5.77 kB  [rendered]
    [ng] chunk {78} 78.js, 78.js.map () 25.5 kB  [rendered]
    [ng] chunk {79} 79.js, 79.js.map () 26.4 kB  [rendered]
    [ng] chunk {80} 80.js, 80.js.map () 8.06 kB  [rendered]
    [ng] chunk {81} 81.js, 81.js.map () 8.07 kB  [rendered]
    [ng] chunk {82} 82.js, 82.js.map () 16.1 kB  [rendered]
    [ng] chunk {83} 83.js, 83.js.map () 16.1 kB  [rendered]
    [ng] chunk {84} 84.js, 84.js.map () 63.5 kB  [rendered]
    [ng] chunk {85} 85.js, 85.js.map () 63.6 kB  [rendered]
    [ng] chunk {86} 86.js, 86.js.map () 28.7 kB  [rendered]
    [ng] chunk {87} 87.js, 87.js.map () 28.9 kB  [rendered]
    [ng] chunk {88} 88.js, 88.js.map () 16.1 kB  [rendered]
    [ng] chunk {89} 89.js, 89.js.map () 16.7 kB  [rendered]
    [ng] chunk {90} 90.js, 90.js.map () 28.7 kB  [rendered]
    [ng] chunk {91} 91.js, 91.js.map () 29 kB  [rendered]
    [ng] chunk {92} 92.js, 92.js.map () 20.4 kB  [rendered]
    [ng] chunk {93} 93.js, 93.js.map () 20.4 kB  [rendered]
    [ng] chunk {94} 94.js, 94.js.map () 11.2 kB  [rendered]
    [ng] chunk {95} 95.js, 95.js.map () 11.2 kB  [rendered]
    [ng] chunk {96} 96.js, 96.js.map () 16.2 kB  [rendered]
    [ng] chunk {97} 97.js, 97.js.map () 16.5 kB  [rendered]
    [ng] chunk {98} 98.js, 98.js.map () 23.3 kB  [rendered]
    [ng] chunk {99} 99.js, 99.js.map () 24 kB  [rendered]
    [ng] chunk {100} 100.js, 100.js.map () 7.68 kB  [rendered]
    [ng] chunk {101} 101.js, 101.js.map () 7.69 kB  [rendered]
    [ng] chunk {102} 102.js, 102.js.map () 10 kB  [rendered]
    [ng] chunk {103} 103.js, 103.js.map () 10.1 kB  [rendered]
    [ng] chunk {104} 104.js, 104.js.map () 10.6 kB  [rendered]
    [ng] chunk {105} 105.js, 105.js.map () 10.8 kB  [rendered]
    [ng] chunk {106} 106.js, 106.js.map () 18.2 kB  [rendered]
    [ng] chunk {107} 107.js, 107.js.map () 18.3 kB  [rendered]
    [ng] chunk {108} 108.js, 108.js.map () 16.1 kB  [rendered]
    [ng] chunk {109} 109.js, 109.js.map () 16.1 kB  [rendered]
    [ng] chunk {110} 110.js, 110.js.map () 17.6 kB  [rendered]
    [ng] chunk {111} 111.js, 111.js.map () 17.6 kB  [rendered]
    [ng] chunk {112} 112.js, 112.js.map () 34.1 kB  [rendered]
    [ng] chunk {113} 113.js, 113.js.map () 35.4 kB  [rendered]
    [ng] chunk {114} 114.js, 114.js.map () 10.6 kB  [rendered]
    [ng] chunk {115} 115.js, 115.js.map () 10.8 kB  [rendered]
    [ng] chunk {116} 116.js, 116.js.map () 14.4 kB  [rendered]
    [ng] chunk {117} 117.js, 117.js.map () 14.6 kB  [rendered]
    [ng] chunk {118} 118.js, 118.js.map () 39.6 kB  [rendered]
    [ng] chunk {119} 119.js, 119.js.map () 39.7 kB  [rendered]
    [ng] chunk {120} 120.js, 120.js.map () 30.6 kB  [rendered]
    [ng] chunk {121} 121.js, 121.js.map () 30.6 kB  [rendered]
    [ng] chunk {122} 122.js, 122.js.map () 10.7 kB  [rendered]
    [ng] chunk {123} 123.js, 123.js.map () 10.8 kB  [rendered]
    [ng] chunk {124} 124.js, 124.js.map () 14.9 kB  [rendered]
    [ng] chunk {125} 125.js, 125.js.map () 15.2 kB  [rendered]
    [ng] chunk {126} 126.js, 126.js.map () 25.5 kB  [rendered]
    [ng] chunk {127} 127.js, 127.js.map () 26.4 kB  [rendered]
    [ng] chunk {128} 128.js, 128.js.map () 5.11 kB  [rendered]
    [ng] chunk {129} 129.js, 129.js.map () 5.18 kB  [rendered]
    [ng] chunk {130} 130.js, 130.js.map () 23.1 kB  [rendered]
    [ng] chunk {131} 131.js, 131.js.map () 23.2 kB  [rendered]
    [ng] chunk {132} 132.js, 132.js.map () 21.6 kB  [rendered]
    [ng] chunk {133} 133.js, 133.js.map () 22.1 kB  [rendered]
    [ng] chunk {134} 134.js, 134.js.map () 12.9 kB  [rendered]
    [ng] chunk {135} 135.js, 135.js.map () 13.1 kB  [rendered]
    [ng] chunk {136} 136.js, 136.js.map () 3.84 kB  [rendered]
    [ng] chunk {137} 137.js, 137.js.map () 3.87 kB  [rendered]
    [ng] chunk {138} 138.js, 138.js.map () 30.8 kB  [rendered]
    [ng] chunk {139} 139.js, 139.js.map () 30.8 kB  [rendered]
    [ng] chunk {140} 140.js, 140.js.map () 11.4 kB  [rendered]
    [ng] chunk {141} 141.js, 141.js.map () 11.7 kB  [rendered]
    [ng] chunk {142} 142.js, 142.js.map () 23.2 kB  [rendered]
    [ng] chunk {143} 143.js, 143.js.map () 23.4 kB  [rendered]
    [ng] chunk {144} 144.js, 144.js.map () 35 kB  [rendered]
    [ng] chunk {145} 145.js, 145.js.map () 36.1 kB  [rendered]
    [ng] chunk {146} 146.js, 146.js.map () 2.47 kB  [rendered]
    [ng] chunk {147} 147.js, 147.js.map () 2.49 kB  [rendered]
    [ng] chunk {148} 148.js, 148.js.map () 5.66 kB  [rendered]
    [ng] chunk {149} 149.js, 149.js.map () 5.79 kB  [rendered]
    [ng] chunk {150} 150.js, 150.js.map () 31.8 kB  [rendered]
    [ng] chunk {151} 151.js, 151.js.map () 32.2 kB  [rendered]
    [ng] chunk {152} 152.js, 152.js.map () 12.1 kB  [rendered]
    [ng] chunk {153} 153.js, 153.js.map () 12.3 kB  [rendered]
    [ng] chunk {154} 154.js, 154.js.map () 16.2 kB  [rendered]
    [ng] chunk {155} 155.js, 155.js.map () 16.6 kB  [rendered]
    [ng] chunk {156} 156.js, 156.js.map () 30.2 kB  [rendered]
    [ng] chunk {157} 157.js, 157.js.map () 30.2 kB  [rendered]
    [ng] chunk {158} 158.js, 158.js.map () 2.92 kB  [rendered]
    [ng] chunk {159} 159.js, 159.js.map () 1.34 kB  [rendered]
    [ng] chunk {160} 160.js, 160.js.map () 5.58 kB  [rendered]
    [ng] chunk {161} 161.js, 161.js.map () 12.7 kB  [rendered]
    [ng] chunk {162} 162.js, 162.js.map () 18 kB  [rendered]
    [ng] chunk {163} 163.js, 163.js.map () 7.89 kB  [rendered]
    [ng] chunk {164} 164.js, 164.js.map () 2.61 kB  [rendered]
    [ng] chunk {165} 165.js, 165.js.map () 181 kB  [rendered]
    [ng] i ｢wdm｣: Compiled successfully.

4.0.0-beta.12 ionic serve:

    [INFO] Browser window opened to http://localhost:8100!

    [ng] i ｢wdm｣: wait until bundle finished: /
    [ng]
    [ng] Date: 2018-09-27T09:16:50.206Z
    [ng] Hash: a07662b38c1281ab7df4
    [ng] Time: 63857ms
    [ng] chunk {common} common.js, common.js.map (common) 29 kB  [rendered]
    [ng] chunk {home-home-module} home-home-module.js, home-home-module.js.map (home-home-module) 5.58 kB  [rendered]
    [ng] chunk {login-login-module} login-login-module.js, login-login-module.js.map (login-login-module) 18 kB  [rendered]
    [ng] chunk {main} main.js, main.js.map (main) 207 kB [initial] [rendered]
    [ng] chunk {page-page-module} page-page-module.js, page-page-module.js.map (page-page-module) 39.1 kB  [rendered]
    [ng] chunk {polyfills} polyfills.js, polyfills.js.map (polyfills) 226 kB [initial] [rendered]
    [ng] chunk {register-register-module} register-register-module.js, register-register-module.js.map (register-register-module) 16.1 kB  [rendered]
    [ng] chunk {runtime} runtime.js, runtime.js.map (runtime) 8.16 kB [entry] [rendered]
    [ng] chunk {styles} styles.js, styles.js.map (styles) 36.2 kB [initial] [rendered]
    [ng] chunk {166} 166.js, 166.js.map () 12.1 kB  [rendered]
    [ng] chunk {vendor} vendor.js, vendor.js.map (vendor) 6.28 MB [initial] [rendered]
    [ng] chunk {0} 0.js, 0.js.map () 14.7 kB  [rendered]
    [ng] chunk {1} 1.js, 1.js.map () 1.27 kB  [rendered]
    [ng] chunk {2} 2.js, 2.js.map () 2.36 kB  [rendered]
    [ng] chunk {3} 3.js, 3.js.map () 1.39 kB  [rendered]
    [ng] chunk {4} 4.js, 4.js.map () 8.11 kB  [rendered]
    [ng] chunk {5} 5.js, 5.js.map () 5.14 kB  [rendered]
    [ng] chunk {6} 6.js, 6.js.map () 23.5 kB  [rendered]
    [ng] chunk {7} 7.js, 7.js.map () 23.7 kB  [rendered]
    [ng] chunk {8} 8.js, 8.js.map () 63.9 kB  [rendered]
    [ng] chunk {9} 9.js, 9.js.map () 64.1 kB  [rendered]
    [ng] chunk {10} 10.js, 10.js.map () 31.1 kB  [rendered]
    [ng] chunk {11} 11.js, 11.js.map () 31.1 kB  [rendered]
    [ng] chunk {12} 12.js, 12.js.map () 16.1 kB  [rendered]
    [ng] chunk {13} 13.js, 13.js.map () 16.1 kB  [rendered]
    [ng] chunk {14} 14.js, 14.js.map () 20.9 kB  [rendered]
    [ng] chunk {15} 15.js, 15.js.map () 20.9 kB  [rendered]
    [ng] chunk {16} 16.js, 16.js.map () 35.1 kB  [rendered]
    [ng] chunk {17} 17.js, 17.js.map () 36.3 kB  [rendered]
    [ng] chunk {18} 18.js, 18.js.map () 19.9 kB  [rendered]
    [ng] chunk {19} 19.js, 19.js.map () 20 kB  [rendered]
    [ng] chunk {20} 20.js, 20.js.map () 24.1 kB  [rendered]
    [ng] chunk {21} 21.js, 21.js.map () 24.9 kB  [rendered]
    [ng] chunk {22} 22.js, 22.js.map () 7.67 kB  [rendered]
    [ng] chunk {23} 23.js, 23.js.map () 7.68 kB  [rendered]
    [ng] chunk {24} 24.js, 24.js.map () 15.9 kB  [rendered]
    [ng] chunk {25} 25.js, 25.js.map () 15.9 kB  [rendered]
    [ng] chunk {26} 26.js, 26.js.map () 23.3 kB  [rendered]
    [ng] chunk {27} 27.js, 27.js.map () 24 kB  [rendered]
    [ng] chunk {28} 28.js, 28.js.map () 8.95 kB  [rendered]
    [ng] chunk {29} 29.js, 29.js.map () 9.19 kB  [rendered]
    [ng] chunk {30} 30.js, 30.js.map () 16.2 kB  [rendered]
    [ng] chunk {31} 31.js, 31.js.map () 16.6 kB  [rendered]
    [ng] chunk {32} 32.js, 32.js.map () 12.2 kB  [rendered]
    [ng] chunk {33} 33.js, 33.js.map () 12.4 kB  [rendered]
    [ng] chunk {34} 34.js, 34.js.map () 31.1 kB  [rendered]
    [ng] chunk {35} 35.js, 35.js.map () 31.1 kB  [rendered]
    [ng] chunk {36} 36.js, 36.js.map () 2.47 kB  [rendered]
    [ng] chunk {37} 37.js, 37.js.map () 2.49 kB  [rendered]
    [ng] chunk {38} 38.js, 38.js.map () 34.8 kB  [rendered]
    [ng] chunk {39} 39.js, 39.js.map () 36.2 kB  [rendered]
    [ng] chunk {40} 40.js, 40.js.map () 16.1 kB  [rendered]
    [ng] chunk {41} 41.js, 41.js.map () 16.1 kB  [rendered]
    [ng] chunk {42} 42.js, 42.js.map () 28.9 kB  [rendered]
    [ng] chunk {43} 43.js, 43.js.map () 29.1 kB  [rendered]
    [ng] chunk {44} 44.js, 44.js.map () 11.2 kB  [rendered]
    [ng] chunk {45} 45.js, 45.js.map () 11.2 kB  [rendered]
    [ng] chunk {46} 46.js, 46.js.map () 58 kB  [rendered]
    [ng] chunk {47} 47.js, 47.js.map () 58.4 kB  [rendered]
    [ng] chunk {48} 48.js, 48.js.map () 11.6 kB  [rendered]
    [ng] chunk {49} 49.js, 49.js.map () 11.8 kB  [rendered]
    [ng] chunk {50} 50.js, 50.js.map () 13.8 kB  [rendered]
    [ng] chunk {51} 51.js, 51.js.map () 13.9 kB  [rendered]
    [ng] chunk {52} 52.js, 52.js.map () 9.71 kB  [rendered]
    [ng] chunk {53} 53.js, 53.js.map () 10.1 kB  [rendered]
    [ng] chunk {54} 54.js, 54.js.map () 16.3 kB  [rendered]
    [ng] chunk {55} 55.js, 55.js.map () 16.3 kB  [rendered]
    [ng] chunk {56} 56.js, 56.js.map () 12.7 kB  [rendered]
    [ng] chunk {57} 57.js, 57.js.map () 13 kB  [rendered]
    [ng] chunk {58} 58.js, 58.js.map () 13.6 kB  [rendered]
    [ng] chunk {59} 59.js, 59.js.map () 14.1 kB  [rendered]
    [ng] chunk {60} 60.js, 60.js.map () 18.2 kB  [rendered]
    [ng] chunk {61} 61.js, 61.js.map () 18.3 kB  [rendered]
    [ng] chunk {62} 62.js, 62.js.map () 11.1 kB  [rendered]
    [ng] chunk {63} 63.js, 63.js.map () 11.1 kB  [rendered]
    [ng] chunk {64} 64.js, 64.js.map () 42.9 kB  [rendered]
    [ng] chunk {65} 65.js, 65.js.map () 43 kB  [rendered]
    [ng] chunk {66} 66.js, 66.js.map () 12.1 kB  [rendered]
    [ng] chunk {67} 67.js, 67.js.map () 12.3 kB  [rendered]
    [ng] chunk {68} 68.js, 68.js.map () 39.6 kB  [rendered]
    [ng] chunk {69} 69.js, 69.js.map () 39.7 kB  [rendered]
    [ng] chunk {70} 70.js, 70.js.map () 22.9 kB  [rendered]
    [ng] chunk {71} 71.js, 71.js.map () 23 kB  [rendered]
    [ng] chunk {72} 72.js, 72.js.map () 11.1 kB  [rendered]
    [ng] chunk {73} 73.js, 73.js.map () 11.1 kB  [rendered]
    [ng] chunk {74} 74.js, 74.js.map () 48.1 kB  [rendered]
    [ng] chunk {75} 75.js, 75.js.map () 48.1 kB  [rendered]
    [ng] chunk {76} 76.js, 76.js.map () 4.43 kB  [rendered]
    [ng] chunk {77} 77.js, 77.js.map () 4.49 kB  [rendered]
    [ng] chunk {78} 78.js, 78.js.map () 16.2 kB  [rendered]
    [ng] chunk {79} 79.js, 79.js.map () 16.2 kB  [rendered]
    [ng] chunk {80} 80.js, 80.js.map () 34.7 kB  [rendered]
    [ng] chunk {81} 81.js, 81.js.map () 36.1 kB  [rendered]
    [ng] chunk {82} 82.js, 82.js.map () 10.8 kB  [rendered]
    [ng] chunk {83} 83.js, 83.js.map () 10.9 kB  [rendered]
    [ng] chunk {84} 84.js, 84.js.map () 17.6 kB  [rendered]
    [ng] chunk {85} 85.js, 85.js.map () 17.6 kB  [rendered]
    [ng] chunk {86} 86.js, 86.js.map () 12.1 kB  [rendered]
    [ng] chunk {87} 87.js, 87.js.map () 12.3 kB  [rendered]
    [ng] chunk {88} 88.js, 88.js.map () 8.81 kB  [rendered]
    [ng] chunk {89} 89.js, 89.js.map () 9.07 kB  [rendered]
    [ng] chunk {90} 90.js, 90.js.map () 11 kB  [rendered]
    [ng] chunk {91} 91.js, 91.js.map () 11.1 kB  [rendered]
    [ng] chunk {92} 92.js, 92.js.map () 13.8 kB  [rendered]
    [ng] chunk {93} 93.js, 93.js.map () 13.9 kB  [rendered]
    [ng] chunk {94} 94.js, 94.js.map () 34.6 kB  [rendered]
    [ng] chunk {95} 95.js, 95.js.map () 35.8 kB  [rendered]
    [ng] chunk {96} 96.js, 96.js.map () 23.4 kB  [rendered]
    [ng] chunk {97} 97.js, 97.js.map () 23.5 kB  [rendered]
    [ng] chunk {98} 98.js, 98.js.map () 48.1 kB  [rendered]
    [ng] chunk {99} 99.js, 99.js.map () 48.1 kB  [rendered]
    [ng] chunk {100} 100.js, 100.js.map () 16 kB  [rendered]
    [ng] chunk {101} 101.js, 101.js.map () 16.5 kB  [rendered]
    [ng] chunk {102} 102.js, 102.js.map () 21.8 kB  [rendered]
    [ng] chunk {103} 103.js, 103.js.map () 21.8 kB  [rendered]
    [ng] chunk {104} 104.js, 104.js.map () 8.06 kB  [rendered]
    [ng] chunk {105} 105.js, 105.js.map () 8.07 kB  [rendered]
    [ng] chunk {106} 106.js, 106.js.map () 10.6 kB  [rendered]
    [ng] chunk {107} 107.js, 107.js.map () 10.8 kB  [rendered]
    [ng] chunk {108} 108.js, 108.js.map () 23.6 kB  [rendered]
    [ng] chunk {109} 109.js, 109.js.map () 23.6 kB  [rendered]
    [ng] chunk {110} 110.js, 110.js.map () 24 kB  [rendered]
    [ng] chunk {111} 111.js, 111.js.map () 25 kB  [rendered]
    [ng] chunk {112} 112.js, 112.js.map () 28.9 kB  [rendered]
    [ng] chunk {113} 113.js, 113.js.map () 29.1 kB  [rendered]
    [ng] chunk {114} 114.js, 114.js.map () 30.2 kB  [rendered]
    [ng] chunk {115} 115.js, 115.js.map () 30.2 kB  [rendered]
    [ng] chunk {116} 116.js, 116.js.map () 15.3 kB  [rendered]
    [ng] chunk {117} 117.js, 117.js.map () 15.6 kB  [rendered]
    [ng] chunk {118} 118.js, 118.js.map () 63.8 kB  [rendered]
    [ng] chunk {119} 119.js, 119.js.map () 63.9 kB  [rendered]
    [ng] chunk {120} 120.js, 120.js.map () 32.8 kB  [rendered]
    [ng] chunk {121} 121.js, 121.js.map () 33.2 kB  [rendered]
    [ng] chunk {122} 122.js, 122.js.map () 30.6 kB  [rendered]
    [ng] chunk {123} 123.js, 123.js.map () 30.6 kB  [rendered]
    [ng] chunk {124} 124.js, 124.js.map () 32.2 kB  [rendered]
    [ng] chunk {125} 125.js, 125.js.map () 32.6 kB  [rendered]
    [ng] chunk {126} 126.js, 126.js.map () 17.7 kB  [rendered]
    [ng] chunk {127} 127.js, 127.js.map () 17.7 kB  [rendered]
    [ng] chunk {128} 128.js, 128.js.map () 5.66 kB  [rendered]
    [ng] chunk {129} 129.js, 129.js.map () 5.78 kB  [rendered]
    [ng] chunk {130} 130.js, 130.js.map () 57.9 kB  [rendered]
    [ng] chunk {131} 131.js, 131.js.map () 58.3 kB  [rendered]
    [ng] chunk {132} 132.js, 132.js.map () 11.2 kB  [rendered]
    [ng] chunk {133} 133.js, 133.js.map () 11.2 kB  [rendered]
    [ng] chunk {134} 134.js, 134.js.map () 7.68 kB  [rendered]
    [ng] chunk {135} 135.js, 135.js.map () 7.69 kB  [rendered]
    [ng] chunk {136} 136.js, 136.js.map () 10.6 kB  [rendered]
    [ng] chunk {137} 137.js, 137.js.map () 10.8 kB  [rendered]
    [ng] chunk {138} 138.js, 138.js.map () 11.3 kB  [rendered]
    [ng] chunk {139} 139.js, 139.js.map () 11.5 kB  [rendered]
    [ng] chunk {140} 140.js, 140.js.map () 16.2 kB  [rendered]
    [ng] chunk {141} 141.js, 141.js.map () 16.2 kB  [rendered]
    [ng] chunk {142} 142.js, 142.js.map () 16.2 kB  [rendered]
    [ng] chunk {143} 143.js, 143.js.map () 16.5 kB  [rendered]
    [ng] chunk {144} 144.js, 144.js.map () 3.84 kB  [rendered]
    [ng] chunk {145} 145.js, 145.js.map () 3.87 kB  [rendered]
    [ng] chunk {146} 146.js, 146.js.map () 21.6 kB  [rendered]
    [ng] chunk {147} 147.js, 147.js.map () 22.1 kB  [rendered]
    [ng] chunk {148} 148.js, 148.js.map () 16 kB  [rendered]
    [ng] chunk {149} 149.js, 149.js.map () 16.6 kB  [rendered]
    [ng] chunk {150} 150.js, 150.js.map () 5.66 kB  [rendered]
    [ng] chunk {151} 151.js, 151.js.map () 5.79 kB  [rendered]
    [ng] chunk {152} 152.js, 152.js.map () 5.21 kB  [rendered]
    [ng] chunk {153} 153.js, 153.js.map () 5.29 kB  [rendered]
    [ng] chunk {154} 154.js, 154.js.map () 14.6 kB  [rendered]
    [ng] chunk {155} 155.js, 155.js.map () 14.9 kB  [rendered]
    [ng] chunk {156} 156.js, 156.js.map () 5.21 kB  [rendered]
    [ng] chunk {157} 157.js, 157.js.map () 5.28 kB  [rendered]
    [ng] chunk {158} 158.js, 158.js.map () 7.89 kB  [rendered]
    [ng] chunk {159} 159.js, 159.js.map () 2.61 kB  [rendered]
    [ng] chunk {160} 160.js, 160.js.map () 2.92 kB  [rendered]
    [ng] chunk {161} 161.js, 161.js.map () 1.34 kB  [rendered]
    [ng] chunk {162} 162.js, 162.js.map () 5.87 kB  [rendered]
    [ng] chunk {163} 163.js, 163.js.map () 12.7 kB  [rendered]
    [ng] chunk {164} 164.js, 164.js.map () 210 kB  [rendered]
    [ng] chunk {165} 165.js, 165.js.map () 15.7 kB  [rendered]
    [ng] i ｢wdm｣: Compiled successfully.

The app's content is enirely the same for each version. Nothing else changed except the verion of ionic.

Ionic info

ionic (Ionic CLI)          : 4.1.2 (...\npm\node_modules\ionic)
Ionic Framework            : @ionic/angular 4.0.0-beta.7
@angular-devkit/core       : 0.7.5
@angular-devkit/schematics : 0.7.5
@angular/cli               : 6.2.3
@ionic/ng-toolkit          : 1.0.8
@ionic/schematics-angular  : 1.0.6

Answer 1

TL;DR - Update NodeJS to v10+

I had to update the current version of Node.js (not the LTS version). It should significantly shorten the amount of time needed to compile.

I don't consider this as a good answer since I have no idea how it solves it, and it shouldn't happen. It's probably a bug. But I decided to post it anyway since it solves this problem.

Answer 2

There's a few new things we're doing under the hood of Ionic to split the code into smaller chunks when building. Meaning that the initial build might take a bit longer, but it will produce smaller code chunks, which in turn will produce a faster initial load